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Originally a manga by Yoshihiro Togashi, YuYu Hakusho tells the story of Yusuke Urameshi, a bitter, beleaguered, junior high punk—and legendary street fighter. One particularly bad day gets worse for Yusuke after he dies saving the life of a small boy from a car accident. He discovers that the forces of the Spirit World were expecting the boy to miraculously survive the accident but did not expect Yusuke to even be a part of it. Because of this surprising(if ultimately useless)Heroic Sacrifice, they offer Yusuke a chance to return from the dead. With the help of Botan (a perky female shinigami "Angel of Death" or essentially "Grim Reaper") and the approval of Koenma (the snarky son of King Enma, the judge of the dead in the Buddhist belief system, and the part-time stand-in for his father) Yusuke returns to the living world.But Koenma has other plans for Yusuke, as both his fighting ability and new found spirit awareness makes him a prime candidate to be a Spirit Detective, an agent of the spirit world hunting down renegade demons who threaten peace on Earth. With much reluctance, Yusuke takes on the job, and finds himself facing all manner of supernatural baddies. Lucky for him, he has the help of Botan as a liaison and tactical support. Early on in his career they send him to the Old Master Genkai, a short, crotchety old woman who nevertheless is a highly capable spiritual guru and martial artist.As his closest teammates he gathered some more-than-capable fighting partners in the form of Kazuma Kuwabara, his old school rival; Kurama, a benevolent reformed fox-spirit trapped in a human body; and Hiei, a not-so-benevolent, not-so-reformed demon who reluctantly tags along with Yusuke and his entourage as part of his sentence.During YuYu Hakusho's initial run in Japan, it was one of the few shows to compete at all with Dragon Ball Z during the early '90s. It is a classic shonen anime featuring colorful characters, lots of humor, and very clever fights. It wasn't as popular in the States as other series, but was one of the first anime to air (mostly uncut) on [adult swim], until it migrated to Toonami with an edited weekday version. However, its fans are very hardcore. It was among Funimation's earliest shows to dub alongside Dragon Ball Z, and therefore, starred some of its earliest regular cast members and kickstarted their reputation. Then-19-year-old Justin Cook, who was the Line Producer and played the lead role, is now the chief producer at the studio. In the Philippines, the series was titled "Ghost Fighter" (and with different character names) and went on to be one of the landmark anime series there as well.Character Sheet is here.
This show provides examples of:
A True Story In My Universe: In the last few minutes of the second-to-last episode several hints are given, and then in the preview for the final episode Yusuke says "well, the secret's out" and it's finally revealed: the show you've been watching is a compilation of footage taken by Spirit World as they monitored Yusuke's adventures.
Mukuro's father is a more direct example of downright evil treatment.
Yusuke's mother Atsuko is not exactly devoted. She's an alcoholic who neglects, beats, and screams at him (no wonder he's become a punk). And on top of that, she leaves her son's dead body surrounded by loads and loads of trash, which nearly gets burned in an arson.
Color Jump pages (while admittedly a limited, sober palette) have Kurama with black hair. The anime...does not.
Togashi's own color illustrations sometimes also depict Kurama with violet hair instead of black (most notably on the second kanzenban cover), and he vacillates between having Botan as blue-haired or blonde. The anime settled on going with blue hair for Botan.
Genkai and Koenma are blond in some of the colored artwork for the manga, with Koenma's uniform being green instead of purple.
Adaptive Ability: Kuro Momotaro uses Steaming Spheres to gain an immunity to whatever attack was last used against him.
Addiction Powered: Chu in the Dark Tournament arc in the uncut version. Cartoon Network's Toonami-edited version has Chu as a fighter who seems like a bumbling fool, but is very skilled and dangerous.
Affably Evil: Sensui's main personality, Shinobu, shows some signs of this, talking respectfully to Yusuke as if they were having tea and crumpets together. Just make sure you shake◊ his hand◊ when◊ he asks◊ you to◊.
And This Is for...: Invoked by Yusuke in the Dark Tournament Arc, while pummeling the particularly odious Dr. Ichigaki, who has beaten the snot out of Kuwabara and enslaved innocent martial artists.
Another Dimension: Itsuki traps Kuwabara, Kurama, Hiei, and Kiyoshi Mitarai in a pocket dimension while Yusuke is fighting Sensui.
Anti-Hero: Yusuke (Pragmatic Hero), Kurama (Loveable Rogue) and Hiei (Nominal Hero). Though Hiei could theoretically shift to Unscrupulous Hero when Yukina is involved. He also shows more heroic tendencies when dealing with Kurama and Mukuro. Kuwabara would be a normal hero in most other settings, but he's got enough hardscrabble streetfighting background to qualify here.
Arc Number: Seven for the Sensui arc. It's declared that the "seven" will dig a grave for humanity, but it's seven personalities; Itsuki remarks that Sensui saw all of his followers as expendable.
Armor-Piercing Slap: Keiko's usual punishment for Yusuke acting up. You would think Keiko was the most powerful force on earth with how often the guy gets beat on by her.
Yusuke's Spirit Detective tools, they get phased out around the time of the Dark Tournament. This bit actually gets lampshaded by Botan when she laments that Yusuke never bothered to use them.
Hiei's true demon form. In the case of Hiei's true form, he was originally supposed to be a Starter Villain, but then he got Saved by the Fans and promoted to a main character. His true form got phased out as well. There's also the fact that putting something as vulnerable as an eye all over your body would probably work against whatever powerup a full demon form would give.
Asshole Victim: Gonzou Tarukane and Butajiri, who are both killed by Younger Toguro under Sakyo's orders. And the rest of the Black Black Club as well, for that matter. They end as victims when Sakyo (himself a member of the BBC) has Younger Toguro kill the other remaining members when they try to stop him from completing his plan.
Assimilation Backfire: When Sensui Seven member Gourmet eats Elder Toguro to get his powers, Elder Toguro ends up taking over his body later.
Ass Kicking Equals Authority: Invoked by Yusuke and played straight by the entire demon world during the Demon World Unification Tournament arc.
Barred from the Afterlife: At the beginning, delinquent Yusuke dies saving a child from being hit by a car, which puts the Celestial Bureaucracy in a bind: He was scheduled to go to Hell, but his Heroic Sacrifice partly redeemed him... but not enough to qualify for Heaven. He ends up working for them fighting demons.
Bash Brothers: Yusuke and Kuwabara do this most often. Toguro and Genkai long ago might have been something between this and a Battle Couple.
Sensui sends Game Master, a little boy whose psychic powers bring games to life, to stall the team from rescuing Kuwabara. The game he chooses to play has the villain die when the player wins, meaning they have to kill the boy to get to Sensui. Sensui counts on Koenma using a large chunk of his spirit energy stored in his pacifier to bring the boy back to life, ensuring that the Mafukan seal that that energy would otherwise go towards would not be strong enough to hold Sensui, so he could continue to Demon World.
Seen several times in the Dark Tournament arc. Arc Villain Toguro at the higher reaches of his strength produces an aura which dissolves weaker demons. Of special note is Toguro's unwilling subordinate Bui, whose major power is literally and explicitly called Battle Aura; he uses it to fly and shoots pieces of it for attacks. The reason for Bui's insanely heavy armor is that Bui's raw power is greater than his fine control, and he can't turn the aura off. The armor acts a Power Limiter to keep his aura restrained until he decides to take his armor off.
Becomes more common as the series goes on. Yusuke starts showing one in the Dark Tournament. The Chapter Black arc Big Bad's aura is so strong it physically prevents energy attacks from hitting him. Yusuke, Yomi, Mikuro, and Raizen's old friends each produce massive auras in the Demon World Tournament.
The Sensui arc focused on this for the most part, the Kaitou and Gamemaster fights being the best to define this.
The series as a whole was one of the first to exploit fighting strategically in mid battle rather than pummeling others with the superior powers.
Beam-O-War: Yusuke and Rando's Rei/Spirit Guns colliding with each other, Yusuke's Rei/Spirit Gun colliding with Chu's Suiken yoki orbs twice, Yusuke's full power Rei/Spirit Gun being canceled out by Sensui's smaller yet just as powerful Resshuu Kou Kyu Ha.
Belligerent Sexual Tension: Yusuke and Keiko. They fight constantly from the very first episode, but they clearly care a lot about each other.
Subverted after the Saints Beasts Arc. While we tend to see them argue with each other more often than not in their interactions, neither Yusuke nor Keiko seem to refute the notion that they're in a relationship (or something at least akin to it). Yusuke mentions to Toguro that he hopes to "grow old" with her after winning the Dark Tournament, and a lot of the set-up to the Demon Kings arc involves Yusuke clarifying his hopes to marry her by the series' end.
Gonzou Tarukane. While he is dangerous thanks to his wealth and his connections (being the founder of the Black Black Club, and hiring various demons and humans to do his dirty work), he overestimates his chances of winning, loses everything when Younger Toguro is defeated, and doesn't compare well to most of the antagonists in the series. It doesn't help that The Toguro Bros were actually working for the real Big Bad, who had caused him to lose his money, and that they end up killing him after this is revealed.
Some of the arc villains in the Dark Tournament are pretty haughty, but end up getting taken out with relative ease. Most notably are Shishiwakamaru and Suzuki from Team Uraotogi, who are each primed to be intimidating foes, yet each lose easily to a severely weakened Genkai.
Also, Risho of Team Masho, who takes particular glee in the potential of taking victory over Team Urameshi, even though it would mostly be by technicality (the only loss they actually inflicted was on Kurama, whereas Yusuke, Genkai and Hiei were all kept at bay by a bogus call from the Tournament Committee and a trap from outside the ring). Then comes Kuwabara, who - despite suffering from crippling injuries - easily wipes the floor with Risho once he realizes Yukina is watching the fight.
Big Brother Instinct: Threatening and later possessing Kurama's little stepbrother was a very, very stupid move. Threatening Yukina will get you cut up by Hiei pretty quickly.
Big Good: Koemna throughout the entire series. Genkai as well from Chapter Black onward.
Bigger Bad: In the manga King Enma is responsible for just about everything, in the name of keeping his public image as powerful as possible—after all, Team Urameshi work for him, so if they take out a criminal, he can take credit for it.
Bilingua|Bonus / Stealth Pun: The dub is littered with these for people who speak both Japanese and English. To sub fans who are monolingual in English, these lines sound like straight-up Bowdlerisation- the most infamous being "A mulberry (kuwa) is a tree, and Kuwabara's a man!"
As for the original Japanese, is it an accident that Yusuke's "Rei Gun" is, well... a ray gun?
Subverted when Hiei faces an enemy with a weapon far stronger than his sword. Blocking the thing actually cuts his sword and bracing it with his arm cuts his arm. He only gets a draw by taking a hit to make him drop his guard.
Also subverted in the final battle between Toguro and Yusuke. Yusuke sends the most powerful attack he could muster against Toguro and he blocks it and eventually stops it after an intense struggle. Toguro then dies because the strain of blocking it was equal to taking the hit.
Bloodless Carnage: A jarring moment in the Chapter Black arc. Yusuke blows an opponent's arm off with his Spirit Gun and not one drop of blood is shown. Odd because The Dark Tournament showed some fairly graphic dismemberments.
Bloodbath Villain Origin: Sensui's villain origin involves him walking in on a group of humans torturing demons, his worldview is shattered, and in a fit of madness he kills everyone there. Also, part of the atrocities the humans committed against the demons was bathing in their blood.
Board to Death: What happens during the Dark Tournament when Sakyo reveals his plan to open a gateway to the Spirit World to the rest of the Black Black Club, and then has Toguro kill them when they object.
Body to Jewel: Yukina's tears, apparently this is part of being an ice demon.
Mukuro's back story went from being her father's sex slave who disfigured herself to keep herself from being molested by him in the manga to being an already cybernetic slave who couldn't remove the shackles from her arms even after she escaped and had to pay for her freedom with the flesh from half her body. Still badass either way.
Similarly, Kurama Taking The Sword in Yusuke's fight against Hiei, deliberately cutting his hand, and throwing his blood in Hiei's eye was toned down to him simply jumping in front of Hiei and backhanding him.
Bread, Eggs, Milk, Squick: At the end of the Dark Tournament Arc in the uncensored anime, right before Genkai comes back to the group, Yusuke says, "Back to skipping Detention." Kuwabara says, "Video Games." Kurama says, "My human family." And Hiei finished the series with "Various Crimes."
Kuwabara zig zags the trope. He is never one of the more powerful fighters and actually loses more than wins in the Dark Tournament (one time being teleported out of the ring by the same basic ability, used by two different fighters). But he has enough pluck and his spirit awareness continually manifests new abilities that keep him relevant and helpful even though, strictly speaking, he is far from the most powerful fighter.
Cannot Spit It Out: Subverted, of all couples, by Yusuke and Keiko! According to Keiko's dad, Yusuke's favorite way to make up with Keiko after a fight is to propose marriage.
Cast Full of Pretty Boys: The True Companions' gender ratio is pretty much 50/50—somewhat skewed by Atsuko and George Saotome, though—but the only girls who really get any spotlight and character development are Genkai and Mukuro. The others have their moments, but the guys are pretty much the focus of the show. There aren't many female villains, either.
Cerebus Syndrome: The manga starts out as an episodic comedy about Yusuke and Botan as ghosts trying to help the living with their problems. After a couple volumes of this, it abruptly shifts into shonen action mode. This gets far fewer complaints from fans than many Cerebus Syndrome victims, however, because most fans know the series from the anime adaption, which skips the comedic stories from the manga and rushes ahead to the action portion.
During the final arc the show suddenly becomes less action-oriented and for the first time focuses on how the events actually affect Yusuke and the gang's everyday lives, suddenly showing several episodes filled with lots of character development and quiet drama as opposed to high-speed punching and explosions.
Changed My Mind, Kid: Hiei leaves the rest of the team during the Chapter Black arc, claiming he has no loyalty to the human world. Yusuke assures everyone else that "he'll come and rescue us in the end when we need him the most." He does.
Character Magnetic Team: At the beginning, it was only Yusuke and Botan. By the Dark Tournament arc, four more members join to form the Five-Man Band, six more by the end of that arc, three allies by the Sensui arc and finally over a dozen by the final arc. The majority were former enemies in some form or another.
Charles Atlas Superpower: Some of the contestants in Genkai's tournament are just normal humans, but presumably through training managed to get abilities like a Spirit Gun or bulking up his arm for a super strong strike.
The biggest one is when Koenma describes the difference between spirit and life energy to Yusuke in the fifth episode. When drained of spirit energy in the climax of the Four Saint Beasts saga, Yusuke taps into his life energy for a Heroic Sacrifice.
There was also "Goblin City" in the Chapter Black saga, a video game Yusuke plays at the arcade during the time Kuwabara is fighting Seaman. About six episodes later, guess what the team has to play against Game Master?
The Mafuukan (Koenmna's pacifier. This also explains why he wouldn't let Ogre remove it during the Dark Tournament).
The egg Yusuke throws into the fire to save Keiko early in the series is Puu! It gets lampshaded when Koenma has to remind Yusuke about the egg during the Dark Tournament arc, as he'd completely forgotten about it after he came back to life.
The "mysterious" masked fighter that comes to the Dark Tournament as the gang's fifth member is obviously Genkai, even wearing the same robes as her and having her characteristically short stature. Despite this, nobody notices until unmasking time comes... sort of. Kuwabara flat-out asks Yusuke if Mask is Genkai, and Yusuke pretty much tells him, "That's what I thought, but s/he said no." Kuwabara is pretty firm in thinking this, until the mask gets ripped and young Genkai is shown beneath it. Genkai's fighting style has the body's cells rejuvenated to the time they were strongest when it's used. It's... really something of a Double Subversion.
Right after Yusuke comes back from the dead he explores the town in sunglasses and messed up hair. And goes unnoticed.
In that same episode there's also a certain blue-haired fortune teller with a fake sounding accent who knows about Yusuke, so you can understand why he couldn't tell it was Botan in disguise.
Clear My Name: After coming back to school, Yusuke was framed by one of the teachers in hopes of getting him expelled. This was quickly cleared up after Yusuke received his first case.
Yusuke pretty much loses his upper clothing in almost all of his major fights. His opponents sometimes do as well. Taken to its logical extreme in his fight against Yomi, where after taking a volley of energy blasts, his shirt explodes off his body. Not a fiery one, mind you, but still. This is flat out pointed out in the actor's commentary for the episode where Justin Cook and co. discuss the characters' tendency to lose their shirts right before the aforementioned shirt explosion. They then wonder what the characters' pants are made of to prevent them from being destroyed as well.
Hiei's shirt is usually either ripped off or thrown off by the end of most of his battles.
Lampshaded by Koto (the announcer cat-girl): "Well, they've burned their skin, shortened their breath, and somehow lost their shirts. All in all, I'd call this a successful fight."
Cold Sniper: This role is fulfilled by the character of... Sniper. Although he's not a sniper as the idea evoke; he doesn't actually use a sniper rifle and he doesn't do a lot of hiding. He can attach his spirit energy to both his target as well as any random objects, resulting in said objects homing in on the target at incredible speeds. From dice, to rocks, to knives and forks, to even gasoline tankers. Later in the fight, however, he opts for a good old fashioned pistol.
The ending to the second-to-last episode and essentially the main point to the whole Three Kings Arc is this, as George/the Narrator so explains. Supposedly, now that Yusuke is done kicking ass in Demon World, his next adventure is to allow himself to "grow up". There are also other sprinklings and hints of the "coming of age" theme throughout the series. Though mainly adhering to Yusuke, this applies to Kuwabara and Keiko as well.
In-Universe, it's implied that carrying the role of Spirit Detective was this for Kuroko Sanada, as well. She started training for the job while fourteen and rather obese, and through building her skils (and attaining a sudden growth spurt), managed to slim down into something resembling a young, female Sensui, which then led to a pretty successful run on the job. After accomplishing quite a bit during her tenure, she chose to retire so that she could move on and form a family of her own.
The Kekkai barrier is used to separate the Human World from the Demon World. Unfortunately, this Containment Field only sort of acts like a net to only filter and keep out A- and S-Class-ranked demons.
L/Ruka tries it on Hiei. She somehow manages to live through it.
Kurama was a demon fox before he was injured in a botched robbery and merged with a human fetus to recover his energy. When the Spirit World SDF arrive near the end of the Chapter Black arc, several of them mention that one of them was the one who injured him.
When Botan sees Yusuke's appearance after his Mazoku transformation, she remarks that she's having flashbacks of Rando, a villain from Season 1.
Cruel Mercy: Why did Hiei spare the Ice Maidens? Because he realized they were dead inside and exterminating them would have put them out of their misery. He also does the same in the Dark Tournament: when a defeated Bui asks Hiei to finish him, Hiei just tells him to kill himself and go away.
The first time Hiei fights on the good guys' side, he slashes up the guy that pissed him off before his opponent could even start to attack. Most of Hiei's battles are like that: Hiei's first battle in the Dark Tournament takes a few minutes because he doesn't attack, then he incinerates his FIRE USER foe; later in the Dark Tournament, Hiei faces Makintaro and cuts his arm the very moment the referee starts the match, and when Makintaro insists on fighting Hiei finishes him with a blade in the brain; against Bui, the two play a little, then, after Bui apparently wins by throwing his Death or Glory Attack back at him, Hiei unveils that such an action only powered him up and defeats Bui with a POKE and a punch; Hiei's "battle" with Sniper consists of Hiei appearing from nowhere and piercing him with his blade; also, Hiei's battle with Sensui, only this time Hiei is on the receiving side. Hiei isn't exactly a Fragile Speedster, but he can't take a punch as well as most of the team, and can easily attack someone's vitals, so the only question is which side of the Curb-Stomp Battle he's on.
The three members of Team Toguro apart from Younger Toguro, vs. Team Gorenja in the semifinals. Karasu blows one member to pieces before he can do much, Bui instantly dismembers his foe with his axe, and Elder Toguro, taking on the remaining three at once, defeats them all instantly, killing one and weakening the other two so that he can finish them off easily.
Genkai's matches against both Shishiwakamaru and Suzuka in the Tournament Semi-Finals turn out to be this. Made all the more notable because both had been hyped up as sizable threats before then (each had made quick work of Kuwabara, teleporting him outside of the ring). Even Hiei and Kuwabara seemed to treat them as formidable opponents. However, Genkai (despite being severely weakened after giving much of her energy to Yusuke just before) makes quick work out of each of them, without so much as breaking a sweat.
Sensui vs. Yusuke (round one, anyway), then Sensui proceeding to kick the collective asses of Youko Kurama, Hiei AND Kuwabara.
Yusuke, after awakening his demon half, kicks the ever loving piss out of Sensui when it takes over.
Yusuke's fight against Sniper was so very much this. In all his experience, Yusuke was always used to fighting enemies head on, but never against somebody who methodically kept his distance and chipped away at him. If it wasn't for Hiei's big damn heroic moment, Yusuke would've been dead a second time.
The battle of Shura vs his father Yomi also counts. Shura even tricks Yomi into getting in close, only to blast him point blank in the face with an energy blast that resembled a nuke. Yomi didn't feel a thing. Kid never had a chance, and as Yusuke notices that he's closer to Shura's level than Yomi's, he suspects that neither does he.
Early in the series, before Yusuke died, he used to hand these out to Kuwabara every time they fought, but Kuwabara keeps coming back for more because he sees Yusuke as his rival.
Kuwabara versus Elder Toguro. Elder Toguro No Selled a few of Kuwabara's sword attacks and chipped away at him, but didn't manage to land any hits that mattered before Kuwabara literally beat him into the ground.
Darkest Hour: The Chapter Black arc is where the series takes a darker turn in general. Near the end of the arc, Sensui kills Yusuke (and Puu dies as a result). The tunnel to Demon World becomes complete. Yusuke's Heroic Sacrifice awakens greater power in his friends, who attempt to avenge his death in a three-on-one battle against Sensui, but fail nonetheless. At the end of the episode "Attempting Revenge", Kuwabara, Kurama and Hiei fall helplessly before Sensui, knowing that even after their friend's sacrifice, they still failed him.
Dark Is Not Evil: At worst, most demons play pranks on humans.) At least in the manga. For most of the series, they do seem extremely bloodthirsty. It's explained away in the manga by King Yama brainwashing demons in order to set up cases, but in the anime just has Enki "change the system" and the way demons act once he becomes King of Demon World.
Darker and Edgier: Many fans profess that the Chapter Black arc is a stark contrast with most episodes before it - and usually for the better. Included, but not limited to are some serious moral dilemmas for the characters, considerably different kinds of adversaries where simple fisticuffs won't win any fights, a deranged and disturbed villain who's not in it for the good fight, but the absolute succession of his agenda, and an overall creepier and more ominous atmosphere. Most fans would cite Chapter Black as the series at its most mature and at its peak.
Day in the Limelight: Hiei and Kurama each get 2 episodes in the last arc detailing their backstories in full, and show how they ingratiate themselves to life under their respective Demon Kings (Mukuro for Hiei, Yomi for Kurama).
Dead Sidekick: Played with during the Dark Tournament arc, where Yusuke's friends exploit the trope by faking Kuwabara's death at the hands of Toguro so that Yusuke's anger and grief will give him the power needed to defeat Toguro.
Narrator: This is our hero, Yusuke Urameshi. There's only one problem: he's dead.
Death by Irony: Gouki who eats souls for a living dies by taking a blast of spirit energy into the mouth.
Death Glare: Hiei is really good at these along with being a hostile Perpetual Frowner. However, what is truly impressive is that when really pissed off, both Yusuke and Kurama managed to pull Death Glares that make any of Hiei's look like fluff in comparison.
Demoted to Extra: After the Chapter Black Saga, Kuwabara only sits around and studies. Atsuko is another example.
Depraved Homosexual: Subverted, played around with, possibly averted and inverted with Sensui.) Played straight with Karasu.
Deus ex Machina: During Yusuke's fight with Yomi in the Demon World Tournament, Yusuke gains the upper hand when he spontaneously generates a new kind of energy. Everyone at first thinks it's sacred energy, but then Hiei exclaims that "No! It's something completely different!"
Yusuke's revival and subsequent victory over Sensui came totally out of left field when he's randomly revealed to be descended from one of the three S-class kings of the Demon World who can take control of his body at will...
Disappeared Dad: Yusuke and Kuwabara's dads, but they are both Back for the Finale. Kurama's human father is also dead, although he does later acquire a stepfather when his mother remarries.
A couple minor, "why even bother?" ones in the FUNimation dub, too.
Suzuki -> Suzuka (changed back in the remastered dub)
Shuuichi (Kurama's stepbrother) -> Kokoda
Kirishima (Kuwabara's friend with brown hair) -> Miyamoto
Sawamura (Kuwabara's friend with the buzz cut) -> Komada
Dub Text: Mostly with Itsuki. Some of his lines are completely made up. The bit about stalking Sensui(etc.) was neither in the manga nor in the Japanese version of the anime.
Also, Toguro and Genkai's relationship 50 years ago got a Relationship Upgrade from the manga and original Japanese in the dub.
Dude Looks Like a Lady: In one of the earlier chapters, Yusuke fights a bewitching Femme Fatale who tries to use her femininity to make opponents underestimate her, trying to play on an opponent's Wouldn't Hit a Girl sense of chivalry. After a Crotch Grab Sex Check, Yusuke finds out it's just a regular guy fighter dressing like a girl to trick opponents. Yusuke even berates him for not being a real transvestite, in one of the series' odder moments of open-mindedness on Yusuke's part. Miyuki accuses Yusuke of violently attacking her because of 'what she is'. He calls her out, saying if s/he hadn't been in the way of the mission, he wouldn't have attacked her at all. Starts about 6:10.
During the final chapters of the manga, the usually calm Kurama is mistaken as a girl (more exactly, everyone thinks he's Kuwabara's girlfriend), which really gets under his skin. Later, Keiko and Yusuke ask him to infiltrate a girls-only school to help them solve a case, and he nearly snaps on them.
Even Bad Men Love Their Mamas: Kurama's relationship with his human mother, Shiori, is what turned him into a decent person. He was originally planning to leave her once he regained his powers, but after she was injured protecting him, he decided to stay.
Toguro refuses his elder brother's offer for assistance prior to his match with Yusuke in the Dark Tournament finals, right before smacking the crap out of him. When elder Toguro gets angry and remarks that they sold their souls together, younger Toguro responds, "That may be. But I never sold my standards.") The fact that he had basically bad-mouthed his former lover he had killed the last night and disgraced her memory didn't help at all.
Earlier, he openly condemned Botajiri's attempts to rig the match against Team Masho. He specifically wanted Yusuke to level up and give him a good challenge. He didn't care if Yusuke died before that fight, but he didn't want him out of the tournament based on a technicality.
Also, the usually amoral and even sadistic referee Koto seriously objects to two of Team Masho's members' dirty methods of fighting and Botajiri's rigging of the matches.
Kurama and Hiei have always been the series' most popular characters.
Everybody Was Kung-Fu Fighting: Though it starts off different, it very quickly becomes about the unusual martial arts the protagonists and antagonists use in battle, especially coming into play during the Demon Tournament arc.
Yusuke is forced to fight someone in complete darkness. His opponent has a helmet-type device that allows him to perceive and alter the flow of energy around and inside him, a) letting him see in the dark (which Yusuke has no way of doing), and b) strengthening parts of his body temporarily. He explains all of this during the fight. The viewer is left screaming at the television for the opponent to just beat the shit out of Yusuke, which he can do with impunity thanks to the Night Vision Helmet.
For the most part, this is actually an averted trope. Explaining Your Powers To The Enemy, while it makes utterly no sense in-universe, is mainly used so the reader/viewer can understand the ability being used. In the anime, the narrator explains the abilities or items characters are using most of the time, and thus this trope stays averted for the most part.
The Dark Tournament arc features this several times (most memorably when a contestant abruptly leaves the ring in the middle of his power-up to go vomit), but it is usually reserved for the comic relief characters of Koenma and Jorge. The dub hangs a lampshade on this and deconstructs it when Koenma yells at Jorge to get up because "surprise time's over" and Jorge replies that his horn got stuck in the floor.
Earlier, in the fourth episode Kuwabara and his gang are pressured to pass their next test and if they don't they will all get kicked out of school. The group talks and explains they need to study to get their grades up. When they ask Kuwabara what he got on his last test he sheepishly responds a Seven. Cue Face Fault.
Toguro, as Genkai's former teammate, seeks his own death at the hands of Yusuke, her student, for reasons only speculated in the series—perhaps as a form of atonement, or to prove to himself that the decision he made to abandon his humanity was a mistake.
The third season Big Bad, Sensui, sought to go to the Demon World simply so that he could intentionally die there as penance after seeing the world inhabited by the creatures he felt remorse over formerly hunting and killing. The fact that Yusuke, a human-demon hybrid, killed him was a bonus.
Elder Toguro, forever bound to the branches of a tree that saps him of his Life Energy and tortured with Kurama-related hallucinations. The tree will not let go or stop until the victim's life force is drained, and as Elder Toguro has nearly unlimited regenerative powers, he will be forever bound, unable to die due to his own healing power.
Younger Toguro willingly chooses one of these after his death: being sent to purgatory.
The demon who blinded Yomi spent 500 years painfully nailed to a wall of Yomi's palace.
What Hiei did to Mukuro's father in the manga. Hiei binds a special plant to him, giving him a healing factor not unlike that of Elder Toguro. Hiei gives the putrid shell as a birthday gift to Mukuro to torture for all eternity. Given what the man did to Mukuro, this is a verykarmicFate Worse Than Death.
Somewhat averted with Sensui. His fate: having his soul never leave his body even after death and thus being confined to eternal sleep and no afterlife, would seem like a Fate Worse Than Death to most, but apparently Sensui actually finds this preferable to being judged by Spirit World in the afterlife.
Flash Step: The only main fighter that doesn't use this is Kuwabara. Because he's too slow. Hiei, in particular, uses them a lot.
Kuwabara actually does do a flash step in his fight against Rinku. Even though Rinku proves to be faster than he'd let on up to that point, he was clearly already moving too fast for an ordinary person to track, and Kuwabara was faster than even that level.
Hiei's speed is much more fun when you consider him cutting the enemy's arm so fast and RETURNING to where he was standing that the enemy did not even know he moved at all. Flash Stepping to your enemy's back? Beginners. Flash Stepping to hurt your enemy and then Flash Stepping back? Expert.
Enemies do it too, of course. A non-battle example: after Younger Toguro finishes his I Am Not Left-Handed demonstration for Yusuke, he finishes it off by flash stepping behind Yusuke to tell him about the Dark Tournament and give him an ultimatum to join.
Flexible Tourney Rules: Boy, are they ever—and intentionally. The Dark Tournament is done as a commercial gig, so teams are allowed to negotiate their own rules and conditions for a match, which adds some variety to the proceedings and makes for a better show.
Flight: Sensui's Seikoki (Sacred Energy) allows him to fly as an angel, which is also why he's also called "Black Angel".
Earlier in the series, there's Jin, who controls and shapes wind to make whirlwinds and other various tricks. Flight is as natural to him as walking.
During the final match against Toguro, Yusuke's spirit energy takes the form of a giant bird and flies around the stadium before it settles back into him, foreshadowing the form Puu (who is a representation of Yusuke's spirit) will eventually take. (Puu also settles down around Yusuke right after taking that form, just like the energy did.)
When Koenma tells Yusuke that Sensui's tunnel to the demon world is going to open much sooner than he originally thought, Yusuke decides to run to the cave and take on the psychics right now. Koenma can be heard screaming "I don't need another rogue agent" in the background before the communication device is shut off.
From the same episode, Kaito claims that Demon's Door (the cave where the tunnel is being "built") is "where scorned lovers go to die". This is likely referring to Itsuki's... relationship with Sensui.
The Id: Toguro, who threw away his sense of right and wrong and let the Blood Knight side of his personality take over. The only reason he has anything resembling a moral code is because he hates anything that will interfere with him getting a good fight (such as Team Urameshi being disqualified on a technicality).
The Superego: Sensui, who sees the world in black and white. There is good and there is evil, with no room in between.
The Ego: Yusuke, who balances out his Blood Knight persona with a firm sense of right and wrong, and the ability to learn from experience when his personal moral viewpoint may not be correct and needs to be adjusted.
Genius Cripple: Yomi, although blind, didn't let that stop him from being the first person in the series to manipulate Kurama, who's known for being the Batman of YYH. And not only that, Yomi gets away with it.
Gentle Giant: Both Kuwabara and Kurama are the tallest members of Team Urameshi but are very compassionate.
Shinobu Sensui stands at least 6' and it would be hard to believe someone like him would ever consider destroying humanity.
Ghostly Gape: Shishiwakamaru can summon ghosts with this kind of face in addition to his sword getting this kind of face via opening it's hilt to reveal that it contains strange, muscular tissue with said face.
Good Is Not Nice: Yusuke and Hiei can be real jerks sometimes, though they are not without their redeeming qualities. Kurama is the same way, but more outwardly pleasant and more subtle with his snarking. Kuwabara is a nice guy, though.
Good Scars, Evil Scars: Subverted. Sensui's scars are multiple, as you'd expect of a villain; however, they are entirely covered by his shirt, as you'd expect of a good guy (because he used to be one). Itsuki becomes scarred over his eye from taking Kuwabara's Rei-ken: a simple heroic scar. Mukuro's scars are also "bad guy" scars that cover half of her body; however, seeing how she got them (by pouring acid over herself to prevent her "father" from raping her as a child), as well as her usual hiding of them, makes them "good guy" markings.)
Gosh Darnit To Heck: The Viz translation is full of hilariously inoffensive language like "holy spit", "dumb cluck", and aloof badass Hiei calling people a bunch of weenies.
Groin Attack: Episode 3 has Yusuke (in his ghost state) taking control of an unconscious young teenage schoolgirl's body so that he can protect Kuwabara who is on his way to school. During his fight against the school thugs that had tried to attack Kuwabara, Yusuke (in the body of the schoolgirl) is able to battle and defeat each of them with no problem and in the end, he delievers three groin kicks to the last thug before knocking him out with a hard right punch. Afterwards, Yusuke leaves the body of the young teenage schoolgirl, who is quite shocked to see on what has transpired.
Growing Muscles Sequence: Toguro undergoes different ones, depending on the percentage of his power he unleashes. Byakko has one every time he absorbs Kuwabara's blows. Chuu gets a small one from drinking a special supernatural alcohol.
Heavy Sleeper: Yusuke early in the Dark Tournament. This is explained as Genkai's training being so strenuous that he has to sleep a lot to recover his energies—though it can be pretty ridiculous when he spends the entire trip to the island, all the way through the first fight in the Tournament, asleep. The smell of alcohol finally wakes him up, because it reminds him of his home.
Heel Face Return: Hiei gets caught by Yusuke for stealing from his boss, but he returns a couple arcs later as an Anti-HeroAloof Ally, and stays that way for the rest of the series.
Hell Seeker: Younger Toguro is one of these, in addition to being a Death Seeker. He chooses to be punished in the deepest level of Hell, even though he could have gotten off with a lighter sentence, because he feels that he could never be punished enough for what he let happen to his old martial-arts pupils and the aftermath of such.
Hello, Nurse!: During the Dark Tournament, a "nurse" is brought out to inspect Hiei and the Masked Fighter after the fight with the Dr. Ichigaki Team. Koenma orders Ogre to hit him on the head so that he can go see the nurse.
Heroic BSOD: During the Dark Tournament final round, where Toguro pretends to kill Kuwabara in order to bring Yusuke's Power Level to his own level, becoming a Worthy Opponent. Interesting though at this time, his Battle Aura becomes the polar opposite of Toguro's own Battle Aura, which killed well over a quarter of the stadium's spectators.
Heroic Resolve: Yusuke tends to get a power-up whenever the people he cares for are about to be killed, allowing him to save them (almost) every time.
Best example played straight is Kuwabara in the Dark Tournament, where he sacrifices himself to Toguro to unlock Yusuke's full power.
—Kuwabara: Hey Koenma, you risked your life on Urameshi's fight and now I'm gonna do the same. So make a place for me, and make sure my wake is as good as his. note Of course it turned out Toguro didn't kill him (and possibly never intended to), but Kuwabara didn't know that going into it. When he realized he wasn't going to die, he played along anyway.
Yusuke attempts to invoke this during the Chapter Black arc after realizing that he's horribly outclassed by Shinobu's (Sensui) Divine Energy. His friends fail as well, though his Demonic Atavism is awakened by his second death, giving him the strength to fight with Shinobu on equal terms
Heroism Incentive: Botan bribes Urameshi with wrestling tickets to go train with Genkai and stop a demon from learning her techniques.
Home Field Advantage: The first of the 4 Sacred Beasts, Genbu, can use his powers over earth to meld with the stone that composes the castle and move freely through it.
Homoerotic Dream: When Yuusuke is trying to come back from the dead, but needs someone to kiss him in order to transfer a spark of life energy to "jump start" him, Kuwabara gets a dream in which he does just that. It gets better: Yusuke had to provide the dream himself (as a ghost, he could communicate through the dreams of the living, and Kuwabara is extremely susceptible. Yusuke did this to help him study for a test once). The kiss has to be from one of the three people who care about him the most—who turn out to be his mother, his not-quite-girlfriend Keiko, and Kuwabara, who was a big time Antagonist in Mourning. Yusuke was horrified, but he did it anyway. Kuwabara thought it was a hellish nightmare, kissing Yusuke's dead body.
Honest Advisor: Yomi recruits Kurama for the purposes of his honest advice. And possibly some revenge, too, but he gives a lot of weight of to Kurama's opinions.
In a late-series one-shot, Yusuke investigates an apparent case of demonic activity at Keiko's school, but realizes that it's only two of the girls trying to force the third to leave because they don't like her performance or attitude on the team. The narrator concludes that humans are perhaps as bad as demons, and possibly worse, especially when Yusuke sells the uniform he borrowed from Keiko to someone online after she refuses to pay him because Kurama did most of the work. Which then gets subverted when Togashi's editor pointed out that Yusuke's a demon at that point.
The Hunter: The "Spirit Detective" job description.
Hyper Awareness: Yomi has six ears, and they are so sensitive that he can hear every word being spoken within the confines of his kingdom. His other senses are improved as well, to the point that he can tell someone is glaring with loathing from their heart rate and the heat from the blood vessels in their eyes.
I Have Your Mother: Kurama is forced to not retaliate against Roto lest Roto order the demon stalking his mother to kill her. Kurama manages to immobilize Roto, steal the trigger to signal the demon, then kill him.
Image Song: Lots of them on the CDs. Each of the four main characters has around three or four songs by themselves, at least one song with other characters and most everyone else has at least one song by themselves.
I'm a Humanitarian: After Yusuke becomes a demon, he no longer regards the casual eating of innocent human beings as an atrocity, and casually tells his ancestor that if eating humans is what will restore his strength, he'll gladly kidnap a few innocent human beings ("really bad ones" in the English dub) and "stuff them down his throat himself" if that's what it takes to get a good fight out of him. He compares it to humans eating hamburgers, saying that a species higher on the food chain preying on one lower is just the natural order, and that humans have simply thought themselves above it.
Ironic Echo: In the Dark Tournament Arc, Kurama gets into a fight with a demonic bomber named Karasu. Early on in the fight, Karasu seems to have the upper hand and as a result mimics putting a pistol to his head and saying, "Bang", indicating to Kurama that he should just simply shoot himself rather than continue fighting Karasu. About ten seconds later, Kurama transforms into his much more powerful true form, and suddenly it's Karasu who's on the ropes. Guess what gesture Kurama decides to make this time.
It Is Pronounced Tro-PAY: Couple names in the dub: Urameshi = Yurameshi, Mitarai ('mee-tah-rye') = Mitari ('mih-tar-ee').
Jerk Ass: Yu Kaito seemingly starts out this way, contemplating whether or not to damage the captured souls of Hiei, Botan, and Kuwabara just to mess with Kurama, but later it's revealed he was on Genkai's side and trying to teach them a lesson about themselves, though whether or not he really meant this remains unknown.
And then there's Kiyoshi Mitari, who laughs and acts up like a jumped-up little egomaniac as he's trying to murder Kuwabara and his friends before he learn he has a Freudian Excuse, and he gets better.
Jerk with a Heart of Gold: Kuwabara is introduces as a delinquent and is shown doing nothing but repeatedly trying to beat up Yusuke. Later after Yusuke dies he sees Kuramabara going through humiliating lengths to save a kitten.
Karma Houdini: The arsonist that lit Yusuke and Atsuko's apartment on fire, which nearly killed Keiko in the process during her recovery of Yusuke's body, is never mentioned to have been apprehended.
Kick Them While They Are Down: Though, he wasn't technically down. Bakken beats the absolute crap out of an unconscious/already badly injured Kurama in the Dark Tournament, claiming that he's still standing and in the ring and therefore must continue fighting.
Kill All Humans: Sensui—subverted because he is a human, among other reasons.
Kiss of Life: Or, Kiss Of Transferred Life Energy, to facilitate Yusuke's resurrection.
Laser Blade: Kuwabara's Spirit Sword. Although it is technically made out of his ki, it still greatly resembles and even sounds like a real Laser Blade.
Last Disrespects: While Kuwabara goes on a screaming fit about Yusuke dying at his funeral in the start of the manga, his outburst is a sign of genuine mourning. In contrast, their school principal calls out some teachers who are at the funeral making snide comments about both Yusuke and Kuwabara's behavior.
Level Grinding: Hiei personally slaughtered hundreds of A-Class demons in order to get himself to S-Class level.
Light Is Not Good: In the manga, it turns out the reports of demon attacks were not only greatly exaggerated, they were set up and the "evil" demons were brainwashed to behave that way, THEN were captured and executed before they could talk. When Yusuke wondered how many innocent demons he may have captured, Kurama advised him to "better not think about that". This plot element was cut out in the anime.
Limited Wardrobe: Played with. Most everyone has their regular attire for the average day, but they can and do change clothes often enough depending on the situation. However, their clothes usually remain assigned by color: Yusuke - green, Kurama - red, Kuwabara - blue, and Hiei - black.
Literary Agent Hypothesis: The entire show is the recordings of Yusuke's career that Koenma had edited as a documentary. His right hand ogre got the job as narrator.
Load-Bearing Hero: The heroes run into a trap like this in Maze Castle, calibrated so that it takes the combined strength of all four of them to hold it up, and that anyone running out would survive at the cost of their friends' lives.
Look What I Can Do Now: Yusuke shows off his new powers after Genkai's training, and Kuwubara does the same a few episodes later.
This being a shounen series, of course, practically every single character absorbs insane amounts of punishment, though usually offenses that produce cutting force seem much more effective at putting people down. Kuwabara, however, takes it Up to Eleven: being not as agile or as quick as Yusuke, Kurama and Hiei are, he tends to get hit a lot in his fights, which does little if anything to shorten them; no matter how many of his bones you break he just takes it and gets back up for more. This is justified in the Dark Tournament by Rishu, who says that a normal human's body would have died by that point but Kuwabara had been subconsciously using his spirit energy to keep his body alive. He frequently deals out such nasty hits that one foe literally ran away from him at the prospect of pummeling him over and over again to no effect while attempting to dodge his Reiken (Spirit Sword) for another thirty minutes.
A more literal example, Gouki almost literally claiming his skin is as hard as steel.
Magic A Is Magic A: There is a lot of random powers that pop up, but there is a broad sense of consistency in how it works. Overall, the different forms of energy, how they manifest and can be used is well documented, with a good portion of the fighting being about strategy instead of raw strength. Genkai and Koenma often have the job of explaining what is going on and, sometimes, why this new ability is still in line with what was previously said.
Magnificent Seven: Subverted and inverted with Sensui's group and Sensui's own personalities.
Masquerading As The Unseen: Subverted when Team Urameshi are accused of this in the Dark Tournament Arc when the Masked Fighter, previously seen as a young woman, is later seen as an old woman. It is quickly cleared up that both are the same person, and that the old woman could become young.
Maybe Ever After: Hiei and Mukuro. It was originally intended to be less vague, but shipper backlash caused it to end the way it did.
Meaningful Funeral: Yusuke's in the first episode. Seeing how much he truly meant to everybody convinced him to undergo the trials to regain his life.
"Urameshi" is what Japanese ghosts who are haunting a house wail; "Kuwabara kuwabara" is a charm against ghosts; "Kurama" and "Hiei" are Japanese mountains said to be sites of demon activity; all of the ferry girls have names associated with flowers and plants ("Botan" - peony, "Ayame" - iris, "Hinageshi" - poppy). This plant naming even goes for Sensui, whose name is a kanji anagram of "suisen" (daffodil) and Itsuki (flowering tree), perhaps to note the severity of their Face-Heel Turn.
Mt. Hiei was forbidden to women until recent history; Hiei inverted this by being born on a floating mountain where men are the ones who are forbidden.
Meddling Parents: Raizen when he possesses Yusuke during his final fight with Sensui.
Men Don't Cry: Completely and utterly averted. During Yusuke's wake, Kuwabara broke down into a histerical sobbing fit, and his friends had to pick him up and drag him out of the room. Yusuke cries for Kuwabara's apparent death in the Dark Tounament.
Mind Rape: Chapter Black is supposed to be watched along with Chapter White to get a balanced look on humanity's potential for great good and great evil. Watching just Chapter Black by itself will drive you nigh insane.
Mistaken for Quake: It is announced that the preliminary round of the Dark Tournament will take place on the ferry to the island. When the ship's deck opens to reveal the fighting ring:
Kuwabara: Aaaah! Earthquake! Hiei: Fool, there can't be earthquakes on the water!
Also the quiz game between Kaito and Game Master. Sure it's a multiple choice test of general knowledge. But then they go to memorizing the whole question database to recognize a certain question with just the first word and press the buzzer or even memorizing the complex formulaic pattern the questions follow to hit the buzzer before even the first word to answer... correctly every time.
Muscles Are Meaningless: Played straight and subverted: Kurama and Genkai possess enormous strength but both are fairly thin, whereas each time Toguro powers up his musculature increases and each of his common levels—20%, 30%, 45%, 60%, 80%—give him a relatively identifiable build. What's odd is that when Toguro powers up completely, Kurama even says, "The structure of those muscles... ingenious." And then absolutely no character around or above Toguro's level follows suit.
Unlike a lot of shonen, the general build of each character does not change as they become stronger. In fact, with the exception of Toguro the size of one's muscles has no bearing on actual strength. Explained by Genkai that the physical body has its limitations, but the augmentation of spirit power to their body is crucial.
Of course, Yusuke's second death led to him being revived as an insanely-powerful demon hybrid that later defeated Sensui.
During the Dark Tournament, Elder Toguro could have easily killed Kuwabara in a single attack, and he wouldn't have even seen it coming. However, he instead chooses to Mind Rape him by telling him that Genkai has been dead for two days and his friends hadn't told him, and that allows Kuwabara to find the strength to defeat Elder Toguro for Genkai's honor.
Not Just a Tournament: The Dark Tournament arc is already pretty, well, Dark, but then it is revealed that the true purpose is for betting and power brokering behind the scenes. The later Demon World Tournament is a complete aversion of this trope, especially considering [Exactly What It Says on the Tin where it takes place]].
Not So Different: A major underlying theme of the series is that the differences between humans and demons morality-wise are baseless. At first it seems that demons are made out to be Always Chaotic Evil. But later we find many humans in the series who are actually worse and many demons who truly have a good heart at least deep down. The case is brought even further in Chapter Black. Then at the end of the manga, it is revealed that in the past, Spirit World residents actually made demons look evil so they could rule, not to mention King Yama brainwashing them. This later became a norm so demons have no obligations of being good and usually turn out evil. But whether one is human or demon, anyone can have just as much potential for good or evil. Well, at least in this show.
Oblivious Younger Sibling: Shuuichi, Kurama's little stepbrother, is completely oblivious to his brother's demonic heritage and supernatural activities.
Odd Friendship: Kuwabara and Hiei. Hiei constantly belittles how much of a dumbass Kuwabara is while Kuwabara keeps up with the short jokes. Kurama even jokes about how one day they might even become in-laws.
Oddly Small Organization: The underworld's cleanup squad for when things go wrong consists of one detective and any friends he might make along the way. Though this is rendered a bit moot by the manga's ending, where it was revealed that Yusuke might not have been needed as badly as we originally thought.
Off Model: Some scenes in the anime have this. For instance, there's a tendency for Sensui to have a really weird, long neck.
In the final volume, Togashi pretty much pairs off EVERYBODY. A rundown:
Hiei and Mukuro is implied but still leaves room for speculation. Kuwabara and Yukina is made much more likely. Yusuke's dad comes back into the picture and gets back with his mom. Chu falls for a new character named Natsume, who eventually returns the sentiment. The trio of Juri, Koto and Ruka admit to loving the trio of Jin, Suzuki and Touya. Koenma and a female reaper also are implied to get together.
Pretty much any time Toguro shows up is an "Oh crap!" for someone.
Bui gets a literal Oh, Crap moment during his fight against Hiei.
Don't forget what happened to Zeru and Ura.
The Kuwabara vs. Elder Toguro fight is filled with this on both sides. Kuwabara gets it most of the times that Toguro reforms himself, and Toguro feels it whenever Kuwabara organizes a counterattack with his Spirit Sword. Epitomized greatly when Kuwabara finally defeats Toguro with his "Spirit Flyswatter", as it was the first time that someone was actually able to hit his vital organs.
Opt Out: Kuwabara didn't participate in the final arc, instead deciding to focus on his academics.
Oral Fixation: Koenma's pacifier, not so out of place in his infant form but much more noticeable in his older and more Bishōnen guise. Apparently, several centuries of soaking in a junior god's essence also makes it a potent magical object.
Overshadowed by Awesome: Kuwabara, although he does develop some techniques that keep him useful despite his lack of power later in the series (his powers made him the pivotal element during Sensui's saga).
Passive-Aggressive Kombat: Kurama, at least twice; at the end of the Four Saint Beasts arc, Hiei mentions how he always has to have the last word; and more literally at the beginning of the Sensui Arc.
Any S-Class fighter. Sensui himself stated that he can't even use 1/5 of his full power because to do so would put too much stress on the planet. Thankfully the Demon World is much bigger and more durable.
According to Sensui, A-Class demons have power roughly equivalent to the gods of various religions and myths (in the dub, he states that they are on par with the Titans of Greek mythology).
Pint-Sized Powerhouse: Hiei and Genkai. Rinku counts, as well. He actually does beat Kuwabara, albeit by fighting dirty
Post Game Retaliation: In Genkai's disciple selection test early on, she has all her applicants get lots of paper. If their paper changed color, they could start her selection trials. If not, they were told to leave. Two self-proclaimed experts angrily attack Genkai over being rejected. She promptly blasts them with spirit energy across the courtyard and into her entrance gate. (It turns out that her paper lots were not random; they only changed color if those holding them had a certain amount of spirit energy.)
Psychic Static: Yusuke does this to Murota. It might be considered a slight subversion; he concentrates simply on exactly what he intends to do. Unfortunately for poor Murota, a straight jab from Yusuke is enough to put him through the wall even if he sees it coming.
Random Power Ranking: The classifications for power are (in increasing order) D, C, B, A, S. note The classification is set up by the Spirit World, so S-class means "anything the Spirit World fighters can't handle", which goes from those just above A-class to true warrior gods whose powers make weak S-class demons look like nothing.
Readings Are Off the Scale/Readings Blew Up the Scale: In the Three Kings arc, a group of Raizen's old training buddies come out of seclusion to pay their respects and join the new tournament. They collectively flex their power to "see if they've still got it" and Yomi's strategist's energy-reading device goes off the scale before it explodes. Miles away from the energy source.
Really 700 Years Old: Koenma, who in fact is precisely seven hundred years old. Kurama in his true form is over a thousand.
Red-Headed Hero: Yusuke's little group has got two red heads in it: Kuwabara and Kurama. Kuwabara is blondish-red while Kurama has dark crimson hair (most of the time).
Red String of Fate: Kuwabara claims his and Yukina's Red String of Fate will lead the group to her. It works (though it's most likely just his high spiritual awareness at work).
Several times Koenma has appeared right behind Yusuke, speaking to and startling him in the process. Botan does this to Yusuke once as well. The entire gag got subverted toward the final matches of the Dark Tournament arc, where Yusuke's spirit energy/reiki level became powerful enough to enable him to detect Koenma's presence as soon as he turned up.
Also Yukina being Hiei's sister. But Kuwabara doesn't know. The other characters like to poke fun at this.
Sacrificial Revival Spell: This was Kurama's reason for stealing the Forlorn Hope, a magic mirror that grants any wish, but kills the user to do so. He was going to use it to save his terminally ill mother. Subverted in that Yusuke prevents this by joining him in the wish, so the Forlorn Hope takes half of each of their lives to save her.
In the Dark Tournament arc, everyone assumes the mysterious masked fighter is a man until the mask is blown off in battle and a young woman is revealed.
Kuwabara: He's—! Yusuke: —a "she!"
In the Three Kings arc, it is assumed Mokuro is a man until she reveals herself to Hiei. It's technically the "Two Kings and a Queen" arc.
School Uniforms are the New Black: Before the Dark Tournament, Yusuke, Kuwabara, and Kurama would go everywhere in their school uniforms. This includes joining a contest to become the pupil of an Old Master in the mountains, attacking the castle of demons intending to take over the human world, and raiding the mansion of an evil rich guy to rescue a Mysterious Waif. Yusuke is an interesting example in that his "uniform" is not in fact the school uniform since he specifically wears the wrong color as a form of rebellion.
Played perfectly straight when Yusuke is faced with the dilemma of killing his mentor to learn her ultimate technique. He refuses, but not immediately. Good thing, too, because if he had refused without hesitating, he would have failed the test as it would have indicated a lack of desire to get stronger.
Genkai loves these: the screening process for the role of her apprentice is full of them, though geared towards strength and ability rather than morality. An ordinary lottery that actually gauges power, seemingly normal arcade games that are altered to gauge spiritual attributes, a booby-trapped forest that only seems like a labyrinth to those who don't have the awareness to travel through it, etc.
Early in the series when Keiko is caught in a fire, Yusuke is told that he could sacrifice the energy he was collecting in his spirit egg (the means by which he could return to life) in order to lead her to safety. He did so without hesitation, which impressed Koenma so much that he offered Yusuke another chance to return to life. Of course, he also had plans to make Yusuke the next Spirit Detective.
Sempai/Kohai: Yusuke was being sarcastic when he called post-Face-Heel Turn Sensui 'sempai', but he's notably more respectful to happily retired Kuroko Sanada than he is to anyone, ever.
Senseless Sacrifice: The absolute worst part of Yusuke's (first) death is that the child he saved was supposed to miraculously survive anyway. Yusuke literally died for nothing. Botan tells him that if Yusuke hadn't shoved the kid out of the way, the little boy would have gotten one less scrape. So Yusuke's sacrifice actually made things worse. Luckily for him, it's the thought that counts.
Serial Escalation: Many, MANY times. The younger Toguro maxing his power to 120% is a good one to cite.
Shoot the Shaggy Dog: The entire Chapter Black saga is an example of this, partially due to Sensui's Batman Gambit above, and partially because Team Urameshi put so much effort into stopping something that the SDF could have done on their own. And Yusuke died, but got better.
Shoulder Teammate: Quite literal. The elder of the two villainous Toguro brothers is often seen riding around on his much larger (but younger) brother's back. Kuwabara even insults him by calling him a "shoulder monkey" at one point.
In a manga-exclusive story, Kurama throws a rose in front of two rival gangs a la Tuxedo Mask. (He actually tells them "Just call me Tuxedo Mask.." while throwing it in the Viz dub.)
Juri's transformation sequence when she recovers from the Idunn Box is based off of Sailor Moon's transformation sequence.
Koenma's disguise in the Demon World Tournament is him wearing the Tuxedo Mask garb.
During the Dark Tournament, there was a shout out to Super Sentai of all things (it's one of the teams ruthlessly offed by the Toguro team; they even use the Himitsu Sentai Goranger codenames).
One of the biggest is how Yusuke dies in the beginning. He saves a child who ran out into the street with a soccer ball, only to later be told that the soccer ball would have cushioned the child, saving the boy's life without leaving a scratch on him. This is a situation that would have, without Yusuke's unfortunate intervention, been exactly the same as what happened to Tsubasa in Captain Tsubasa.
Not to mention when Kuwabara goes to the 'Megallica' concert in episode 75.
When Yusuke and Kuwabara are arguing after their first arrival at Genkai's house, several Street Fighter characters can be seen, including Dhalsim, E. Honda, Zangief (with a scar on his chest instead of all the hair), and middle-aged Ryu.
There is a momentary shout out to The Stars My Destination during the Dark Tournament when an audience member is shown with the N♂MAD tattoo.
In episode 21, there's a glimpse of a poster of Oingo Boingo's "Good For Your Soul" album on the wall in Kuwabara's room. No name changes either, as with "Megallica"; the album's cover is mimicked in full, complete with artist and name.
Sorting Algorithm of Evil: Every new bad guy the heroes go up against is billed as really strong and evil, but after a while, the show makes you ask why Spirit World placed such top priority against nobodies like Kurama and Hiei in the first season. However, it actually works with a bit of Fridge Logic. Because of the barrier, S-Class and A-Class demons can't cross over. So a high B (Toguro) IS the strongest force imaginable, but not someone you would send the new guy after (why Yusuke never heard of him). Sensui was an unknown threat (at least in the dub, Koenma thought he was just some crazy guy who disappeared) and all his forces were strong in different ways (the introduction of territories) and had only activated a few months prior. As for anything beyond Sensui: Those were A- and S-class demons who would never have been a problem because of the barrier. It is sort of like how a cop doesn't have to worry about someone with a nuke (for the most part).
The show is considered to have one of the most broken algorithms in anime because it started to follow the Dragon Ball Z pattern of being completely outclassed by the next Big Bad. The first few major fights Yusuke won by luck (i.e. having moss in his ears and making Rando Hoist by His Own Petard), but once he Took a Level in Badass there was no reason why each set of villains was more powerful than the last.
It's probably Toguro who really kills it. Up until that point, all of the antagonists were relatively equal, to the point that Hiei completely destroyed the penultimate Saint Beast. Then Toguro shows up and he's completely above and beyond anything they've faced, actually pretending to lose. Then he comes BACK and reveals that he was only at 20% power. While the Dark Tournament competitors were probably on a steep power slope, there's no real indication. Yusuke goes through not one but two sudden power-ups to defeat Toguro, & he keeps those power-ups, so the other bad guys need to get stronger. Oddly enough, Sensui admits to being weaker, just more experienced until his seventh personality breaks out the sacred energy. Even Toguro only being a B demon isn't so bad, until they actually GO to Makai and A-Classes suddenly become red shirt armies while low-to-mid S-Classes can take on hundreds at once & supposedly have planet-exploding power. It gets so bad that new characters have to come out of nowhere to claim the title of strongest.
Spontaneous Weapon Creation: At one point, Hiei uses his ability to create a sword made out of Dark Fire. He's reluctant to use this more than he can help though, since it reminds him too much of Kuwabara's Spirit Sword.
Story-Breaker Power: As per Word of God and in-universe examinations Raizen is acknowledged to have formerly been the most powerful demon in the series. Hundreds of years ago when he was in his prime Raizen had a power level so amazing that he could have easily defeated the other Two Kings of Demon World without batting an eyelid. You'd probably then wonder what is preventing Raizen from ending the war between the 3 kingdoms by himself. Raizen does have the potential to regain his old power level, but since he's a breed of demon who gains his power from eating human flesh Raizen's decision to not eat humans out of respect to Yusuke's female ancestor has led to him starving to death. In his weakened state Raizen can't fight like he used to and has retired to his castle waiting for a successor to assume his throne before he dies, Yusuke being said successor. Notably, despite having about a year left before his starvation kills him he can defeat Yusuke's newly acquired S-Class power level with a wave of his hand—like an adult kicking a child's ass, showing that Yusuke is still a runt in the litter as far as S-Class demons are concerned. Hell, it literally takes Raizen being minutes away from death for Yusuke to fight on par with Raizen. For additional perspective, Kurama makes it a point that though the S-Class rank is still an awe-inspiring rank for a demon to attain, there are some demons in the ranks of Demon World that transcend the ranking system so profoundly that they might as well be considered gods; in fact the classing system of S-Class usually just translates into Spirit World lingo for "Demons too powerful for us to handle," and Kurama claims that such demons are rather offended by being classed in a ranking system when there is no way to comprehend their power. Raizen clearly was one of those demons who transcended the ranking system as old comrades/rivals speak of him in his prime with awe and reverence, that he was the most powerful demon alive in their era, and is arguably the most powerful demon that has ever lived—if the Two Kings that rival Raizen's kingdom saw Raizen fight in his prime they would "piss their pants," showcasing that only Raizen's self-imposed weakness has kept this cold war going.
Mad bomb: Out of luck, now you're... [smirks and growls]
Summon Magic: Used by Rando, Kurama with plants, and Hiei with the Dragon of the Darkness Flame.
Supernatural Gold Eyes: Kurama may look like a red-haired, green-eyed young man in his human form, but as soon as he drops the human disguise and turns into his real demonic form, his eyes change to this color. Itsuki also has this type of eyes, and they are a hint that he isn't exactly a human psychic. Elder Toguro has them too.
Talking in Your Sleep: Despite sleeping heavily, Yusuke still reacts accordingly to things that happen around him. He can even fight in his sleep, apparently sleepwalking while dreaming of fighting Genkai; he managed to knock out three opponents who wanted to take advantage of his sleeping state on the ship.
Telepathy: Hiei's Jagan eye grants him this power. Kuwabara also displays it with Yukina in the Rescue Yukina arc.
Teen Pregnancy: Atsuko is 28 when Yusuke dies, meaning she was only 14 when he was born.
Teeth Flying: Happens off-screen in an early episode of the dub. Kuwabara is set upon by a group of thugs while he's taken a vow not to fight at all, even in his own defense. As Yusuke and Botan watch helplessly from the sidelines, Botan makes the horrified observation, "Is that a tooth?".
Truly Single Parent: Yomi clones his son Shura from his own genetic material; also, most of the ice maidens (except, of course, Hiei and Yukina).
Tsundere: Keiko is a Type B; i.e., "more deredere". She's a rather nice Girl Next Door unless provoked. Usually Yusuke provokes her, but a creepy gangster bullying one of her friends caused her to slug him so hard she knocks teeth out. Keiko can be a little bit of a Badass Normal in the strictly human arena.
Unknown Rival: Kuwabara to Yusuke for some time before the start of the series. Kuwabara is gleeful the first time Yusuke remembers his name.
Wolf Man: Koro Momotaro uses one of his Steaming Spheres to transform into his last Beast Armor: the Armor of the Wolf, which resembles a werewolf.
Why Won't You Die?: It's almost comical how Byakko manages to survive not one but two near-death experiences against Kuwabara, with the latter expressing particular shock that the beast was able to survive getting pushed into molten lava. That said, Seiryu is quick to kill him off for real after deeming him a disgrace to the villains.
World of Snark: The whole main and supporting cast with the exception of Yukina. Even some of the villains can turn out snarky at times.
It's implied that Mr. Akashi was hoping Kuwabara would hit him for changing his test to give him a failing grade, so that even if his deception came to light, Kuwabara would still have violated his end of the bargain.
Xanatos Speed Chess: Just about all of Kurama's fights. While he usually has a vague plan going in, he almost always has to rely on a stroke of genius to save the day.
Yaoi Guys: Karasu, Itsuki. Sensui is debatable, since he's not very preoccupied with relationships beyond using people while trying to destroy humankind... but there are very subtle cues in his backstory and in the way he acts.
Yin-Yang Bomb: Toward the end of the series, Yusuke mixes human energy and demon energy. The resulting combination is far more powerful than the two were separately.
Koto (to Botan): Stick to what you're good at, honey, like dying your hairunnatural colors, for instance. Gets lampshaded a second time when Botan rushes to Yusuke to inform him of an update on his current case, and he jokes "What's the problem, ran out of your hair dye?" Koenma even comments on Yusuke's remark, "That's Botan's natural hair color, it makes no sense to joke about it Yusuke."
Youkai: Nearly 80% of all the antagonists in the series and 3/5 of the Nakama.