Schoolrooms all over Japan are abuzz with the rumor of the "Hell Correspondence" (Jigoku Tsushin), a mysterious website which can only be accessed at midnight. If you submit the name of someone you hold a grudge against, you will be visited by Enma Ai, the Hell Girl (Jigoku Shoujo), who will give to you the means to carry out your revenge — a black straw doll with a red string tied around its neck. To take vengeance, all you need to do is pull the red string off the doll, and Ai and her associates will send the target of your grudge immediately to Hell. However, this service is not without a price: as the old saying goes "when seeking revenge, first dig two graves" — by sending someone to Hell, you will have bound yourself into a covenant with Ai, and when you die, you will also go to Hell, as signified by the black fire symbol that appears on your chest once vengeance is served.Such is the premise of Hell Girl, a genre defying, victim of the week, anti-magical girl, social commentaryseries with a Japanese horror edge. Originally broadcast in 2005, followed in 2006 by a second season Hell Girl: Two Mirrorsnote Jigoku Shōjo: Futakomori. This was followed two years later by Hell Girl: Three Vesselsnote Jigoku Shōjo: Mitsuganae.The first season introduces Ai Enma, the Hell Correspondence and the series' episodic format. Each episode introduces a victim and an antagonist, and the circumstances surrounding them. As each story unfolds, the antagonists' actions push their victim further into despair, and it's only through the use of the Hell Correspondence that their victim can overcome their circumstances and send their tormentor to Hell. After the formula has been established, the series introduces a complication into the mix: single father and reporter Hajime Shibata notices the increase in the site's popularity and starts a personal investigation. Aided by his young daughter, Tsugumi, who has a mysterious connection to Ai, he tries to convince users of the Hell Correspondence not to complete the contract, generally making bad situations worse through his meddling.The second season picks up a few years after the conclusion of the first season, and continues the established formula (minus Hajime and co.), this time telling each story from the side of Ai and her associates as they investigate and influence the circumstances in each case. Though diluting the simplicity of the concept, this season swaps out the Black and White Morality found in most of the first season cases for a Black and Grey Morality, in which neither antagonist nor victim is really in the right. Fortunately, the new angle manages to keep the series watchable in spite of the overdose of misery and woe.The third (and possibly final, again) season switches up the formula a third time, introducing a new third angle to the standard format, this time in the form of Yuzuki Mikage, who, through interactions with the victims and Ai's associates, is given the rare opportunity to watch her hometown and her entire life crumble around her courtesy of the Hell Correspondence. Amazingly enough, it goes further downhill from there.The series as a whole is mainly a social commentary, using the Hell Correspondence as a tool to analyze and deconstruct the less appealing aspects of Japanese culture and society (there's even a Nice Boat-inspired episode in Mitsuganae). While many themes are universal, Values Dissonance means some storylines (like Mitsuganae's Wham Episode) are inevitably lost in translation.This anime also has the distinction of airing on American television- IFC holds the broadcast rights to the first season of Hell Girl and shows episodes of it in varying timeslots. Check their website for more details.There is also a manga adaptation, which shares the premise and core characters but follows its own storyline. The first series ran for 9 volumes, the second for a few more, and the third is currently ongoing. A Live-Action Adaptation also exists, in series form; set within the timeline of the first anime season, retaining the anthology format while notably averting the anime storyline. At a mere 12 episodes, there wasn't much room for them anyway. The series also spawned two video games, for the Nintendo DS (Jigoku Shoujo Akekazura) and the PS2 (Jigoku Shoujo Mioyosuga) respectively, as well as a puzzle game on the Konami-Net DX service for i-mode compatible mobile phones.No connection to Hellboy.
Alpha Bitch: Aya Kuroda, the very first person sent to hell in the anime.
Anime First: The anime and manga began releasing almost simultaneously, but the former is the original and the latter the adaptation (anime has a longer lead time than manga). The manga's quite different, and lacks Hajime and Tsugumi except in omakes.
Art Shift: One of the banishments in season three is done entirely with paper cutouts.
Asshole Victim: Most of the time, if the string is pulled, the target was one of these. First subverted in episode 12, where the target is actually Yoshiki Fukasawa, a depressed man who ultimately asks to be killed, and is sad that his student, Akane, the one who killed him has to go to hell as well. It was first inverted in episode 7, where Ayaka seeks revenge on her (strict) adopted mother for not casting her in her show and later for refusing to finalize the adoption. She ends up sent to hell by her rival, who she had sabotaged. Later goes both ways (subverted and inverted) during episode 23.
Badass Grandpa: Wanyuudo. Super strength, martial arts skills, and fire-manipulating/creating powers, if you can look past the fact that he's A sentient, shapeshifted wheel-demon
Bait and Switch: Sometimes, an episode leads us to think one person will be sent to hell, but the target actually turns out to be someone else. A good example is season one, episode 16. The client is a little girl in the circus named Yumi, who is repeatedly locked up and whipped by the ringmaster, while her twin sister, Yuki, is pampered and doted over. At first, it seems obvious that Yumi contacted Hell Girl to send the abusive ringmaster to hell. However, it turns out the target is actually Yumi's twin sister Yuki, who knew about the abuse and never did anything to stop it. There's also a subtle implication in the "flashback" that Yuki did something-or-other to persuade the ringmaster to abuse Yumi, and by the end of the episode after Yuki is sent to hell, the ringmaster is doting over Yumi and the abuse has stopped.
Bishounen: Ren, who uses this to his advantage when required.
Brand X: Everybody uses the GoogleDeegle search engine. Mahoo also appears a few times.
Beware the Quiet Ones: Done a lot, especially during season three. A lot of the quiet, shy, characters end up being cruel and evil.
Broken Aesop: Maybe. One of the aesops of this show is that it's futile to hold grudges and angry feelings in one's heart, because that just digs your own grave as well. It successfully pulls off the Aesop, as far as it goes, by putting a mark on each client's chest and hammering home the fact that the client will be joining his/her tormentor in hell one day (it also pulls off the Aesop through very brief few-second "flashes" of what could happen to the client if they sell their soul, such as episode 3's client being impaled by spikes, episode 4's client being set on fire and screaming in agony, etc.). Here's the part where it's "maybe broken": in some scenarios, the client's associates are very quick to point fingers at the client and start verbally abusing them in anger, often with very little provocation. Episode 6's client's mother is one of the worst examples; she's raped, but her husband thinks she was intentionally cheating on him, and didn't bother to give his wife the benefit of the doubt before he started screaming at her. So the lesson then becomes, "It's wrong to get revenge on others for mistreating you, but mistreating others in the first place, even if it's just as a bystander, will be allowed to pass without comment by everyone around you." One probably doesn't need to describe the Unfortunate Implications of the scenario this would imply...
Brother-Sister Incest: One Squicky episode from the second season (episode 9, more specifically) revolves around a pair of siblings, one of whom, Maho, contacts the Hell Correspondence Website to take revenge on her brother, Mikio, who she feels is deliberately sabotaging her relationships out of spite by dressing up as a woman and hitting on her boyfriends. It's eventually revealed that the real reason he is doing it is because he lusts after her sexually and wants to have her all to himself.
Bumbling Dad: Although he's something of a pathetic loser and a rogue, Hajime Shibata, the journalist, is actually a doting and loving father.
Crapsack World: You can be the nicest guy in the world and someone will still find reason to send you to Hell. You can go to Hell for pissing someone off. Even if they are overreacting or are crazy. You can be sent to Hell for the slightest reasons, or no reason at all. Someone just has to hate you enough. As Mitsuganae shows, you can be sent to hell before even BEING BORN!
That and the general depiction of the world being a filthy, sinful and extremely hateful place.
Creepy Child: Again, Enma Ai. Her gigantic, unnaturally red eyes and white, expressionless face only add to her eeriness. Kikuri, an otherworldly child introduced in the second season, is — thanks to her purple-sclera eyes and her childish sadism — perhaps the only character in the series even more creepy than Enma Ai. This is understandable, seeing as how she's actually an avatar to the Lord of Hell, Enma Ai's boss (although, judging from her reaction when she was being taken over by the Lord of Hell in the ending of the third season, she isn't aware of that).
Kikuri and Ai can be quite cute and amusing when they're interacting with each other, one instance where Ai and Kikuri get into a typical "Yes!-No!-Yes!-No!-etc" argument, so Ai reverse-winds Kikuri's spring (she's possessed a wind-up toy right now) so she can't move. When they're on the job though, man do they ever revert back to the Creepy Child trope.
Season 2 episode 10. The victim of the week is a bum, but he isn't malicious or knowingly evil. What does he get sent to hell for? For scratching a guys car. Accidentally spilling coffee on him was just an additional.
In the first manga series, a school girl sent her teacher to hell because he just happened to be nagging her too much to her liking. She is in turn sent to hell because she took a bracelet from her friend.
Averted in one Futakomori episode, where a truck driver's little brother was killed when he accidentally drove off a cliff, due to design faults in a highway, which were only there because a lonely old man didn't want to move out of his house. The truck driver is about to pull the string when Ai's assistants show up and tell him that the old man has died of natural causes. Truck driver eventually finds out that the old man wasn't as selfish as he thought at the end of the episode and in fact was quite thoughtful. Probably one of the few, if only, episodes where NOBODY went to hell.
The live-action adaptation's Alternate Continuity actually makes it worse, in a way. In the anime, after the soul was sent to Hell, the wisher usually had a little supernatural bonus added to their lives, generally restoring the opinions of people the villain had caused to fall, or making somebody survive who would almost certainly have died otherwise because of the villain. This was probably to emphasize that it was, in fact, a Deal with the Devil, and temporary at best (since it's immediately followed by the sender looking at their brand). In the live-action adaptation? Nope, you have to do all that yourself if you can.
Easy Road to Hell: All that's needed to go to is for someone to dislike you enough to be willing to make a deal to send you there—or to make that deal yourself. People have been sent to Hell for spilling coffee on someone on that show.
Emotionless Girl: Enma Ai. She shows very little emotions, but on the rare occasion she does, you're really screwed.
She'a more of a subversion; she actually has feelings, but after so much time doing her job, she just can't seem to express them anymore. Wanyuudo says he can "hear her heart breaking" in one episode, where an innocent was sent to hell, and although she herself isn't shown crying, her face painted in a wall by one of the persons that made a contract with her starts to shed tears when he is about to die, indicating that she was probably crying at that moment too.
Enjo Kosai: In the first episode, Hashimoto Mayumi is blackmailed into this.
Entitled Bastard: A frequent trait of the hellbound targets. For instance: Aya Kuroda, the Alpha Bitch in episode 1, right up to the point she enters Hell, expresses neither remorse nor regret for essentially ruining Mayumi's life for shits and giggles, and even behaves as if it was her right.
An even better example is the target in episode 3, a male ace baseball player, Mamoru Hanagasa, who murdered a teammate and framed the innocent client, Daisuke, for it in order to create an incident that would be the perfect excuse to call off a game that might put too much stress on Mamoru's shoulder. Unlike Aya above, Mamoru doesn't even bother minimizing what he did as harmless. Rather, his sense of entitlement is so high that he says that others should be honored to die for his talents since he's just that awesome!!!
Even the Girls Want Her: Ai's companion Honne-Onna. Les Yay with Enma Ai aside, she's so admired and wanted by a bunch of girls of a school where she works at during the Mitsuganae season that one of these girls named Yuna tried to send another of Ai's employés, Ichimoku Ren, to Hell out of jealousy, after mistaking them for a couple.
Evil Matriarch: The villain of The Doll Episode is an ancient dollmaker who attempts to mold Inori, her son's young bride into a perfectly compliant living doll. In the end, her son picks up where she left off, for an even worse Downer Ending than normal.
The people of the creepy classroom that give Aya her first scare as her consignment to Hell draws near.
"Facing the Bullets" One-Liner: Sometimes the companions will ask whether the target is sorry for what they've done. Their answer is almost invariably, "No."
Failure Is the Only Option: Somebody always gets sent to Hell, despite any attempts to prevent it (there are exceptions to the rule, but they're very far and few between.)
Fanservice: There are some instances of this. For example, the hot springs episode of Futakomori and the possession scene from Mitsuganae. Was it really necessary for Ai to kiss Yuzuki, while they were both naked in a bathtube, to possess her? And to show Yuzuki her past in the ending?
Faustian Rebellion: Ai and Giles de L'Enfer, alias Hell Boy, who claims to have dragged himself out of Hell through use of his psychic powers.
For the Evulz: One episode has a nurse named Kanako Sakuragi, sent to hell. Most of the episode Tsugumi is spend trying to find out if Kanako had any dark secrets or was a Bitch in Sheep's Clothing, to find out what could've made anyone want to send her to hell. Turns out, the nice and self-sacrificing image is not a front, it's actually how she really is . . . and she gets sent to hell anyway by a guy she doesn't even know who did it just because he could.
One episode revolves around Maki Onda, a girl that wants to send her unknown tormentor to hell. The unknown tormentor writes horrible things on the girl's desk, hides caterpillars in the girl's pencil box, traps the girl in a locker room that appears to be a sadistic Death Trap, and pours hydrochloric acid on the girl's back when they finally meet. And the bully's reasoning? It was an experiment.
Force Feeding: Happens in the first season when a theater actress is cornered by a gang of thugs, and force-fed a tonic that completely destroys her voice.
Genre-Busting: A fusion of suspense, drama and horror, with some slice of life and social commentary about the least appealing aspects of the Japanese society thrown in for good measure. The third season is full of Mind Screw as well.
Genre Savvy: The target in episode 5 of the first season, a Corrupt Corporate Executive, who, unusually for characters of that archetype, is fully aware that her actions will likely mean she's going to hell when she dies. But, she reasons, if she's only going to hell when she dies (until the client sends her to hell at the end of that episode, of course), then while she's alive she might as well have as much fun "winning the game" as humanly possible.
Gone Horribly Right: Sending the person who made your life a living hell, well, to hell does not solve everything.
He Who Must Not Be Seen: Enma Ai's "grandma". All we ever see of her its her silhouette. The only human character that sees her runs away from the house, screaming in sheer terror.
Here We Go Again: The second and third seasons end with someone accessing the Jigoku Tsushin, even though it looked like Ai was finished being Hell Girl.
Heroic Sacrifice: Enma Ai herself, when she refuses to transport the soul of Takuma Kurebayashi, whose life situation somewhat mirrored her own. As a punishment she becomes mortal and later dies while trying to defend the boy from violent townspeople.
She does it again in Mitsuganae to save Yuzuki from being condemned to hell after she oversteps her authority as the new Hell Girl.
Some people pull the string in order to save people they care about.
Idiot Ball: As the series starts to move in a more grey morality, some of the people who summon Hell Girl carry this. And let's not forget that this series is all about people trying to improve their lives by sentencing themselves to eternal suffering. Which might not be the most logical of plans. Some of them outright state that they don't care about going to Hell anyway, just as long as their targets are out of their lives. But considering that the dolls send both the user and the target to Hell, thus forcing them to be in the same place forever, well...
When the old man in season one asks Enma Ai if he will see the man he sent to Hell, she states Hell is a pretty big place.
I Want My Beloved to Be Happy: One episode features a girl named Tae Sakairi, who is so in love with the idea of playing the "victim" of this trope, that she actually becomes distressed when the object of her affection, her childhood friend Kei, rejects the "other woman" and decides to fall in love with Tae instead. Tragedy soon ensues.
Karma Houdini: Subverted by the townspeople of season 2. Sure they've escaped mortal justice but they'll still go to Hell when they die.
Kick the Dog: Many of Ai's targets do plenty of this, driving their victims to seek vengeance through the Hell Correspondence.
A girl named Miki Kawakami has two Welsh Corgis. The evil, greedy, abusive rich woman the girl is forced to keep house for, Chinatsu Shimono, poisons both dogs and then drowns the puppies that the second dog had given birth to the day before. Miki, who had made the contract with Enma Ai but was hesitant to fulfill it, sends the bitch to Hell immediately after finding out about the puppies. Which is literally seconds after the police arrived and arrested the woman for multiple murders, so this could be also interpreted as an act of guilt. "I couldn't stop her in time and I deserve to go to hell for it." (episode 18 of the first season)
A girl named Mioi Hatsumi owns a chihuahua and lives in a building with a woman named Shimatani. Shimatani attempts to get Hatsumi's dog kicked out of the apartment, and finally ends up poisoning the dog and causing Hatsumi to fall off a balcony. Yes, she gets it. (episode 8 of Mitsuganae)
A veterinarian by the name of Yoshiyuki Honjou, who doesn't care about treating the animals in his clinic, and eventually allows young Junko Kanno's dog to die. Yup, another one who gets sent to Hell for being mean to puppies. (episode 4 of the first season)
And of course, there is Leon Yamada, the town bully, who harasses geeks in episode 5 of Futakomori. He sits outside a convenience store one day, playing with a lighter, and a dog comes nearby. Yamada entices the dog to come closer, and when it does, he lights the flame right under the dog's nose. The dog runs off crying in pain, and Yamada laughs wickedly. Oh don't worry... he gets it in the end. Even though he had made the contract in a completely unrelated circumstance.
Large Ham: Wanyuudo in the live-action adaptation.
Little Miss Badass: Enma Ai herself, who takes on the form of a vulnerable young girl clad in either a kimono or a black and red fuku. When angered, she has the power to take out an entire village.
Magic A Is Magic A: A somewhat questionable case. In some episodes it seems to be implied that if the victim shows remorse, even after the string has been pulled, they may yet be saved. However, other episodes seem to indicate that people in this world are sent to hell not because they've done anything wrong, but because they're hated by another person (and could even be sent for no good reason at all). This can, however, be resolved by saying that Ai and her family were simply tormenting the victim before sending him or her to hell.
Also, almost nobody ever actually does show remorse, which means it's never actually tested whether or not they could save themselves if they owned up to what they did. The targets almost always boast that either what they did was insignificant (episode 1's target) or that their actions were ethically justified (episode 11's target) or that the victim had it coming (episode 7's target). And the people who do show remorse are always the ones who for some reason accept being sent to Hell anyway: to name just one example, in episode 12, the schoolteacher repents how he treated the client, but this particular schoolteacher wanted to be sent to Hell, and the fact that his client will soon join him isn't what he wanted at all.
Mind Rape: Before the actual sending-the-target-to-hell segment, this is the form the "banishments" take. The target is first made to go through an inverse illusion of his/her own crime, with other supernatural horrors thrown in to make it worse. For example, Aya, target of episode 1, has a series of pranks pulled on her by other classmates (including faceless-demons-as-classmates) inside a school that rapidly switches from day to night, mirroring the way Aya threw Mayumi's life into chaos. For another example, the target of episode 2, a stalker who almost murdered the girl who sent him to hell, is forced to wander through a hospital where he's first pinned to the floor by skeletons, and then has to watch the girl he stalked cry over her father...who turns into a skeleton that attacks the stalker, all of this mirroring how the stalker had trapped the girl in a sick life and murdered anyone who got in his way.
Mind Screw: Pretty much any time an antagonist is in the interdimension before getting dragged to hell.
In episode 13 of season 1, Hajime Shibata gets a mind screw moment when the porn-shop owner's parakeet starts talking to him.
Minor Injury Overreaction: One episode features a playboy movie director named Tetsuro Megoro. In the end, he's sent to hell by a guy that he accidentally dumped coffee on early in the episode.
The sender is also the guy who's car he scraped up a little deeper into the episode (although the flash-backy nature of the episode can excuse the oversight).
Motive Decay: In the first season, most people who called on Ai Enma did so because they really, really could not expect retribution. This premise is diluted as the plot demands in the next two seasons.
From the first season one notable exception is the girl whose dogs got abducted and later killed (episode 18). She sent her tormentor to hell after the police arrested her and from the findings would go to prison for at least multiple murders. Don't mess with dogs in this series!
Musical Nod: Sakasama no Chou, the opening theme from the first season is used as a ringtone, bowling alley music and on a billboard for the single (in which the music video is shown) in both Futakomori and Mitsuganae. NightmaRe, from Futakomori, gets used in Mitsuganae as well.
No Ontological Inertia: Often the villain getting sent to Hell also makes whatever trouble they caused their victim to be mostly fixed. This gets less and less common as the series goes more into a Grey and Grey Morality.
No Sympathy: There are some rather jarring examples in this series, and not even from the targets the clients have grudges against, either; in several episodes, the client would not have felt the need to send the target to hell if everyone else involved, including the client's loved ones and friends, weren't so quick to assume the worst about the client. Some especially egregious examples include:
the client of episode 1, who is manipulated into having a photograph of her and a male escort taken in town and the principal's first assumption is that the client is a slut, and he calls her to the office to scream at her about this without giving the client a chance to explain herself
the client of episode 3, who's framed for murder merely on the hearsay of the target since everyone else in town is apparently willing to quickly assume guilt without evidence
the client of episode 6, whose mother is raped because of blackmail by the target and the client's father's first assumption is that the client's mother was cheating on him (as opposed to showing concern for his wife who is obviously miserable and crying)
the twin clients of episode 9, since after their secret recipe shows up on TV at the same time as they were trying to show it off in their bakery, the first assumption of the citizens is that the fraud lies with the clients, without even giving the clients a chance to explain their side of the story
the client of episode 11, whose father was framed for corruption by an editor who was really convinced the father was guilty, but the son ends up losing his education, his money, and his home on top of that, and all his supposed "friends" dump him the second he no longer has money. Really, sometimes one wonders why the clients even bother sending the targets to hell, given that the average Japanese citizens as depicted in this show can be so cruel and/or unloving that the client would just be victimized by another target anyway, only without the ability to make a contract since they already used up their chance.
Parental Abandonment: Tsugumi Shibata, the journalist's daughter who has a psychic link to Enma Ai, lost her mother Ayumi in an accident, although notably, the circumstances surrounding this death have a large role to play in the first series' denoument. Enma Ai herself suffered through the deaths of both of her parents. And their tragic murder was explored in a flashback episode. It was revealed at the beginning of the second season, that the parent's souls were being held hostage by the forces of Hell in exchange for Enma Ai's cooperation as one of Hell's agents of vengance.
Also, at the end of the first season, Enma Ai tries to convince Tsugumi to send Hajime, her father, to Hell, by using the memories of her mother Ayumi's death. She fails, though: Tsugumi rejects the deal and Ai leaves her and Hajime alone.
Pocket Dimension: The space where Ai and her associates take the "offender" before they are formally sent to Hell. Has to be this, since 1) Ai still hasn't ferried them through the gate to Hell, and 2) it can't just be a Mind Rape illusion, since we've seen the offender be physically removed from our dimension (easiest to see in the first season due to the Shibatas' involvements)
Also, the place where Ai keeps the candles with the names of everyone that made a contract with her that are still alive. You can go there by entering into a vase inside Ai's home.
The Power of Hate: The Hell Correspondence is an odd example. Anyone who truly hates another person can access it and sell their soul for revenge. Season three shows that this works even if the hatred is induced through hypnosis. Another version of this trope is part of Hone Onna's backstory: she became a Youkai after dying by absorbing the resentment and bitterness of other betrayed women.
Precision F-Strike: Ayaka Kurenai. It's apparently pretty early on that she's not a very good person. The dub translates this by having her swear a mile a minute.
Punch Clock Villain: Ai hangs around the hut and her minions work their day jobs when they're not dragging some poor soul into Hell.
Wanyuudo running his own oden stand was particularly amusing.
Pyrrhic Villainy: Literally. No matter how much better your life becomes after you send someone to Hell, you will be joining them soon enough. And you get a cheerful mark on your chest to always remind you of this.
Although there are a few cases where it's done for the sake of someone else. A girl named Haruka did it to the person who was ruining her mother. And for her sake the mother seems nice to the child of the victim... whether that will hold or not is left unseen.
Reality Warper: Ai seems to be able to do this, as seen when she's sending people to hell and during the season one finale, when she's bullying Tsugumi to make her send her father to hell. Although maybe she was just mind raping her, it's not very clear.
Red String of Fate: Fits mostly to the title of the trope than anything else really. There IS a Red String and it DOES work in binding their Fate, but with no connotations to romance at all. If someone could redirect me to a trope that's more suitable than this, please do so.
Reincarnation: It is implied that Hajime is a reincarnation or distant descendant of Sentarou, a boy Ai cared about during her life, forming part of the driving force for the climax of the first season.
Ret Gone: Records of the past few years of Yuzuki's life begin disappearing. Turns out she's been dead all this time, and this life is a complete illusion.
Hone-Onna does this to two women she befriended at the end of an episode in Futakomori.
She also did this to two office workers she was talking to about an episode's target in season one.
Screw the Rules, I Have Supernatural Powers!: After Yuzuki becomes the new Hell Girl, she immediately attempts to use her powers to take revenge on a woman who had unjustly sent her best friend to hell, not even bothering to listen when Ai's former helpers try to warn her against it. If she had waited one more second she might've learned that this was exactly the one thing she was NOT supposed to do. Would it have stopped her anyway? Debatable.
To Initial D of all things, in episode 10 of season two.
Sins of Our Fathers: When Ai discovers that Hajime and Tsugumi are distant relatives to a childhood friend who ended up helping bury her alive she decides to try and Mind Rape Tsugumi into sending her father to Hell.
Spoiler Opening: Subverted. Mitsuganae's opening credits set it up as the same stand-alone episodic fare of the first two seasons, but this is only to avoid drawing attention to Yuzuki before she's established as an important character, after which it changes to reflect the series's new direction.
Soul Jar: In the third season, a girl named Yuzuki Mikage becomes one for Enma Ai through Demonic Possession. Eventually she becomes Ai's successor.
Stringy-Haired Ghost Girl: Ai sometimes verges on this trope. As it turns out, she was once an onryo before being conscripted into her duties as the Hell Girl.
To Hell and Back: Giles de L'Enfer, if he's to be believed. Due to this, he considers himself a rival of sorts to Ai.
Tomato in the Mirror: One episode which begins with a woman named Shizuko Amagi pulling the string on her straw doll. After that, it shows what led up to this, and at the end it's revealed that Kyoko Tachibana, the recluse who was harassing and playing pranks on her was forced to live the ordeal through the woman's eyes, and the entire misunderstanding could have been cleared up had she just calmly talked it over and told her that she had adopted the cat first.
True Companions: Ichimoku Ren spent an episode considering how their group is like a family. And in season 3, Ai Enma reiterates their group as such to Yuzuki.
Unmoving Plaid: When Ai wears her flower-patterned black kimono, they look like they're greenscreened on. This is likely deliberate, to show the magical nature of her kimono, as the flower pattern on it is used to induce death in victims.
Victim of the Week: Every episode has a different client, and many of them have been abused in a certain way.
Wham Episode: Episode 24 of Mitsuganae: By the way, Yuzuki, you're really just a ghost, and this entire season was a lie.
Xanatos Speed Chess: This is essentially the entirety of the third season, and a good amount of the first and second seasons. In the Third Season the question then becomes ... who is the master of this particular game? The cynical might say its the Lord of Hell playing Ai to trap her as his servant for all eternity ... those with a bit more heart might say it's Ai's desperate gambit to save one innocent soul from Hell.
You Can't Fight Fate: Played straight most of the time (the target of the contract will go to hell if the string is pulled, and the person that pulled it will end up there too after dying), but subverted in some cases; Enma Ai escapes from the Lord of Hell in the ending of the first season even after he said it was her destiny to end up in hell if she ever opened her heart again, and ends up avoiding going to hell at all when everything is said and done. In the end of the second season, Ai saves the life of Takuma even after the string was pulled and he was destined to go to hell. And in the third season, although Yuzuki turns into the new Hell Girl after fighting against it and refusing to accept it as her fate, in the end she does it more of desperation (she was dead all along and never really had the life she tought she had, nor does she had anything left in the normal world) than because she "accepted her destiny"... and she doesn't even keep the position for long anyway.