"I'll show you. This is what it means to kill something."
Shiki Tohno was involved in a major accident in his childhood. Miraculously, he survived, albeit with a weakened body and no memory of the incident or much of the rest of his past. However, when he awoke in the hospital, crooked lines covered everything, from his own body to his bed to the other doctors. He quickly discovered that anything could be destroyed with ease, simply by cutting along those lines. It seemed like the world was in danger of crumbling around him... He would have gone insane had he not come across a mysterious self-styled sorceress, who gave him glasses that hid the "lines of death" and allowed him to live a normal life. Following the incident, Shiki was sent away from the main household to live with a branch family, while his sister was raised as the new heir.Now a high school student, Shiki suddenly receives word from the Tohno estate. The family head, his father, has died, and he is to return at once to the main household. Meanwhile, strange murders have begun to occur in the city, the victims drained of their blood...Originally a Visual Novel, with a fan-translation patch available from Mirror Moon. There is also a manga adaptation (released in English as "Lunar Legend Tsukihime"), an anime adaptation (Shingetsutan Tsukihime), a pseudo-sequel game of short stories (Kagetsu Tohya), and a series of fighting games (Melty Blood) that takes some liberties with the paths from the original game.A remake was announced in April 2008, reportedly finally containing the Satsuki Yumizuka/Sacchin route, one of the running jokes of the franchise. Said remake has no current release date. The ending to the manga (and the DVD Commentary to the second episode of Carnival Phantasm) also add official secondary confirmation that the remake is in the works.An issue of the magazine Type Moon Ace (vol. 8, Dec. 2012) has revealed new pieces of info regarding the upcoming remake, mainly the new character designs .Takes place in the Nasuverse.
Actually Not A Vampire: After encountering a bunch of actual, honest-to-gods vampires, Shiki begins suspecting that his own little sister Akiha is one, too, especially after witnessing her feeding on Kohaku's blood. It turns out that Akiha is not a vampire but a demon hybrid who must consume "bodily fluids" (including blood) of a very specific person (Kohaku or her twin Hisui) in order maintain her sanity.
Adaptational Badass: Everyone in the manga gets more chances to show off compared to the Visual Novel.
This is something he wouldn't have had the chance to do in the Visual Novel since Roa didn't use any magic there and was overall unimpressive.
The manga's art style helps emphasize Arcueid's sheer viciousness and brutality while in battle, and we get to see her dominating the first half of her fight with the Big Bad before her exhaustion catches up with her.
Ciel demonstrates how to pull off a Storm of Blades using Black Keys, and her fight with Akiha shows her tactical acumen and ability to analyze an opponent's strength and weaknesses on the fly.
For her part, when Ciel tries to hide from Akiha, Akiha takes the straightforward option of simply torching the entire forest around her, and later melts Ciel's hand down to the bone with a simple glance.
Adaptation Expansion: On the other hand, it also incorporates elements from other routes and increases the threat level of the Big Bad, which is a very welcome change. There are also differences in the resolution to make it fit into canon more effectively especially the ending, which expands upon the True Ending to make Shiki track Arcueid down after she decides to go to eternal sleep.
A Day in the Limelight: Many of the Ten Nights of Dream side stories in Kagetsu Tohya are from the perspective of somebody else besides Shiki.
A great deal of information from the game is left out in the anime, such as backstories, motivations, how various powers work, and so on. For example, we don't learn much about Shiki's past, his link with Akiha, the nature of Roa's resurrections, and the other Dead Apostles.
However, the game leaves out a lot of information, too—this is the Nasuverse, after all, which is filled with a confusing jumble of extensive explanations of magic, vampires, history, and much much more! To pick up on this you need to read some of the character material and play the follow up games (fighting and visual novel) all with some degree of Alternate Continuity and uncertain qualifications as to what is actually going on.
Alternate Continuity: The original game has five character routes that cannot all be possible in the same universe (see Cutting Off The Branches). The anime makes some deviations of its own. The Melty Blood series is apparently based on a planned-but-never-released route (with Satsuki as the heroine). Stories in Kagetsu Tohya also follow different continuities from each other, following up game routes or making up bizarro scenarios. It's also lampshaded when Shiki tries to remember which year it is in relation to the original story and notices his memories don't make any sense.
Animal Motifs: Tsukihime overflows with cat motifs. Arcueid, the eponymous lunar princess and primary heroine, is the one this can see in most frequently.
Artificial Human: Artificial non-human Arcueid was not born through the normal process that True Ancestors are, which is the world deciding it needs more of them and makes one. Rather, the other True Ancestors decided they needed someone stronger and purer around to deal with all the corrupted True Ancestors and somehow brought Arcueid into being as the closest thing to a perfect True Ancestor there can be.
One part of Ciel's motivation deals with her guilt over being forced to kill everyone in the town she came from. This is also alluded to in Kagetsu Tohya where it becomes clear that she's not really over this.
Akiha is also attempting to Atone for what her father did to Kohaku. This is only made completely obvious however in Kohaku's route when Akiha completely inverts due to absorbing Roa's vampiric nature and possibly soul and as a result STOPS trying to atone and instead just tries to kill Kohaku.
Hell, just name a character. Most likely that character does something incredibly badass at some point in the Tsukihime-Kagetsu Tohya-Melty Blood timeline. Not even Satsuki is immune. Hell, even Arihiko arguably manages this in Kagetsu Tohya.
Badass Family: The Nanaya clan, whom specialize in assassinating demon-hybrids with nothing more than their physical strength and speed and minor psychic abilities. (Kiri's Evil Eye only allowed him to see the auras of people.)
Badass Normal: Nanaya Shiki, our Shiki's delusion of what his inner self is, is an incredibly badass knife fighter that Shiki cannot defeat even oncethough this is also because he had been made to forget about his ability to see death, which he knows is what levels the playing field.
Battle Harem: Shiki's harem includes an ancient vampire who can summon the moon itself, an Executioner from the church, a half-demon hybrid, a succubus, an alchemist and an exceptionally powerful classmate-turned-vampire.
Baleful Polymorph: In Kagetsu Tohya, after hearing some ghost stories involving cat demons from Kohaku, Shiki encounters Arcueid wearing a giant cat costume. After forcibly removing it from her, he ends up falling asleep with the costume in his bed. The next morning, Shiki finds he's turned into a cat. Hilarity Ensues as the other inhabitants of the Tohno mansion show why none of them should ever have pets. Doing so is actually required to reach 100% Completion.
Becoming the Mask: Near Side: Ciel's decision to remain with Shiki. Far Side: Kohaku's True Ending.
Beware the Nice Ones: Kohaku, the sweetest member of the Tohno household, turns out to have been the mastermind behind all the deaths that had occurred the last several years.
Bishonen: Shiki, though more the "manly" kind rather than the "girly" kind, especially with his glasses off. It's just one of the reasons girls flock to him. Okay, just the abnormal ladies but he can't complain and I'm sure most other guys in his situation wouldn't either.
Big Bad: Michael Roa Valdamjong, or the "real" Shiki Tohno in the Far-Side Routes.
Big Screwed-Up Family: The Tohno family. The branch families like the Arimas are pretty normal, but the main family, despite being rather small by the time the game begins, makes up for it in the "screwed up" department. Not to mention the small size is due to being so fucked up it has nearly killed itself off.
In the True Ending for Arcueid's route, Arcueid technically survives, but after saying one last goodbye to Shiki, she leaves to sleep, presumably forever now that Roa is Deader Than Dead. However, the manga ending has him track her down and they reunite, perhaps to keep it consistent with sequels.
Arcueid's is easily matched, bordering into Downer Ending, by the True Ending for Hisui's route, with Akiha killed by SHIKI, Kohaku committing suicide, and Shiki and Hisui leaving the mansion.
Likewise, both of Akiha's "good" endings are bittersweet. In one, Shiki saves Akiha's life by seeminglynote Kagetsu Tohya has a sidestory that continues from this ending which confirms that he lived killing himself so that the lifeforce she lent him will return to her. In the other, Shiki can't kill himself, so Akiha lives out her life as an insane beast that feeds on his blood.
Ciel's good ending is unambiguously happy, on the other hand, unless you're Ciel herself. Why? Because Arcueid cheerfully sticks around and decides to go for a threesome ending of sorts. Ciel is not happy about having to share in her good end. Shiki himself also spends much of his time figuring out how to keep Arcueid and Ciel from killing each other.
Black Comedy Rape: In Arcueid Route Shiki threatens to rape Ciel. Her reaction is rather unexpected.
Shiki: "If you don't listen to me, I'll rape you right there." Ciel: *Death Glare* Ciel: *Dissonant Serenity* "Your proposition is intriguing, but I'll pass."
Blank Slate: Kohaku, though mostly according to her. She was never very expressive and Makihisa's actions made her kill off her own personality even more, leaving her with no idea of who she is or what she wants. Eventually, she just ends up just copying Hisui's cheerfulness. Even after Redemption Equals Sex, she fears that her allegedly 'redeemed' persona might just be her showing Shiki what he wants to see. In Hisui's good ending, where Kohaku's almost totally lost her memory and even takes on a new name. While not ideal, this at least allows her to be what she was before everything went so wrong.
Bleached Underpants: The game contained several sex scenes, both of which (for the specific path in the game) are alluded to in the anime. Also the de-emphasis on one of the two 'bodily fluids' that can supply mana. The manga shows more of this while still keeping it relatively worksafe. Even the Mirror Moon English-translation patch has an option that edits out the nudity and lengthy descriptions.
Blessed with Suck: Shiki's ability to bypass most forms of invulnerability and easily destroy nearly anything with a pocketknife (or his finger, if he so desires) is pretty awesome. Unfortunately, the ability saps his health and risks destroying his mind with every use, as the human mind was not meant to comprehend death in such a way. He would have gone insane from seeing the illusion that the world might crumble at a touch had he not been given indestructible glasses to block his power, and it is implied that his eyes will eventually grow too powerful for even these to contain.
The most blatant example in the game is when Nrvnsqr Chaos slaughters his way through 103 people in a hotel and has fought Shiki and Arceuid to within an inch of their lives... and then just strolls away. Arc later explains it's because his power was waning as dawn approached, but you'd think Chaos could have taken the extra three seconds necessary to kill his opponents. However, Chaos seems to have had a more prolonged death for Arc in mind and doesn't even notice Shiki.
Once you've cleared all the routes (and "Eclipse") in the game, it seems like there's nothing more to do... but click the topmost Kanji for the Mirror Moon Staff Room, the thin bar for a series of gags, and the words "TYPE-MOON" along the bottom for more gags.
Kagetsu Tohya also has 10 short stories, which are unlockable through doing certain actions during the game. Three of these are non canon, but the others are used for world building including one that is actually the epilogue to Akiha's better ending.
The anime inverts the trope. Shiki goes to his sister's bedroom unannounced and catches Akiha sucking Kohaku's blood: the maid effectively being her mistress' breakfast in bed.
Inverted when Shiki and Arcueid first meet: it's the human stalking the vampire. Without knowing Arcueid is a vampire (or, for that matter, anything else about her), Shiki follows her home, breaks into her apartment, and kills her. She gets better.
Gender-flipped when when Tohno Shiki is unable to meet with Arcueid one night, she breaks into his room and watches him sleeping while she waits for him to wake up. Arcueid's behavior is more playful than predatory, although she does have urges to feed she needs to fight, and Shiki's response is neither fear nor attraction, but rather "what the heck is wrong with you?"
Cannot Cross Running Water: Apparently, it makes vampires weak when they attempt to cross water, even if it's stationary. Arcueid gets around this one by simply teleporting around the planet, which is actually portrayed as being something of a hassle and not really a great way to move around. Sumire is an exception, but living underwater has instead made her weaker on land.
Also, the game where Shiki and Akiha wrote their names on things in the mansion to "claim" them. It's unlikely many people thought Shiki and SHIKI would mean two different people.
Chekhov's Gunman: In the first two character arcs, Satsuki plays pretty much no role, saying a handful of lines and then completely disappears from the story. She then reappears in the Far Side arcs, in which you find out exactly WHY.
Chick Magnet: Shiki. Eight or nine women can't all be wrong. Perhaps it's the Tohno Gland? Either way, you have to suspect that Shiki would rather that his love interests be somewhat less crazy.
Childhood Friends: Arihiko and Shiki. Arihiko is probably the person who understands Shiki better than everyone. And that even includes his love interests.
Akiha has minor bouts of jealousy on occasion, but it's not until Kohaku's route (when she's psychotic due to absorbing SHIKI's power) that she starts getting dangerous about it. The drugs that Kohaku had been secretly feeding her do not help either.
Arcueid during Ciel's route. Boy is she freaking scary. The Tohno gland is a mixed blessing eh?
Contract On The Hitman: After Kiri Nanaya, the head of the Nanaya clan of demon/demon-hybrid assassins, retires and leaves the protection of the organization he belonged to, Makihisa Tohno and Kouma Kishima lead an attack on them. After a prolonged battle, Kiri is killed by Kouma, who goes on to slaughter everyone else except Shiki. Both were motivated by personal vendetta: Kouma was attacked and had one of his eyes blinded by Kiri when he was younger during one of his missions, and Makihisa is implied to have been the client for that hit, who Kiri injured while in a rampage.
Cringe Comedy: Almost every optional funny scene. In some cases you get the opportunity to play Shiki like a complete dumbass; telling the truth about your outing with Arcueid is pretty much pure Refuge in Audacity, as Akiha thinks Shiki is joking. The aftermath of Arcueid's erotic dream, when you meet her in the park, is also hilarious and painful.
The anime and manga adaptations follow Arcueid's path (with small additions from other paths). Melty Blood follows the (unseen) Satsuki Normal path. The opening of Kagetsu Tohya implies that it follows either Arcueid's or Ciel's good endings, but 90% of Kagtesu Tohya is a messed up dream that throws continuity for a loop.
This is used for a joke in a KT side story. All five main heroines appear in "Hisui-chan: Inversion Impulse", which follows Hisui's good ending...but since Arcueid never appears in that route, no one but Ciel recognizes her◊.
Deader Than Dead: Doing this to people is Shiki's whole shtick by 'cutting their lines'. He doesn't just kill people's bodies, or kill their souls; he kills the very meaning of their existance, which means he can bring death even to things which aren't alive. It's a power so horrible that it drives him a little bit more mad every time he sees the 'lines', and even the Big Bad calls him a monster when he finally realises precisely what it is Shiki can do. In response, Shiki kills a freakin' corridor to crush him as it implodes.
Depleted Phlebotinum Shells: Conceptual Weapons, the Church's heavy artillery against supernatural threats. Ciel's Seventh Holy Scripture is an example. Shiki's knife is mistaken for one by both Arcueid and Ciel, until they find out that its lethal efficiency is due to Shiki's own power.
Dissonant Serenity: Kohaku tends to take any news of extreme violence or even injuries to herself completely nonchalantly, which Shiki finds a little weird.
Does This Remind You of Anything?: On his way home from school, Shiki stops to catch his breath and watches the crowds of passerby. One beautiful woman in the crowd catches his attention, and he can't take his eyes off her, his pulse races, and he stalks her all the way to her home, seized with an unstoppable urge to kill her. Excitement building within him until he's ready to burst, he manages to force his way into her room and does the deed. The next day, she, understandably upset, tracks him down and forces him to "take responsibility" disbelieving his claim that it was his first time, in light of his considerable skill.
Don't Call Me Sir: Shiki asks Hisui to stop calling him "Shiki-sama" and be less formal. Her response? "As you wish, Shiki-sama." Kohaku does honor Shiki's request, but Hisui continues referring to him as "Shiki-sama" even after their relationship becomes more intimate.
Double Standard Rape Female On Male: After an initial grudge, Shiki quickly gets over the dream Arcueid sends him that involves him more or less being raped by some girl he knows, since it turns out Arcueid didn't know since the particulars of the dream weren't under Arc's control and she was trying to give him a reward for helping her.
Downer Ending: Some of the Dead Ends aren't fatal to Shiki, they're just incredibly sad. Akiha doesn't even get a "Good Ending" alternative to her True Ending; she gets a terribly depressing "Normal Ending."
Dramatic Sit Down: Shiki does this in the videogame when Arcueid disappears. Throughout the day, he is merely going through the motions at school. It was easier for him to go to school than deal with Akiha. He only gets better when after he sits alone waiting for a teacher. He waits for several hours, then Roa and Arcueid show up and start fighting to the death.
Dual Wielding: Ciel and her black keys. In her case, though, it's more Triple Wielding. Or occasionally Sextuple Wielding (three in each hand).
Dysfunction Junction: Not even a minor character like Arihiko is exempt. The Tohno family mansion in particular is practically this trope as a literal geographic location.
Easter Egg: Play the game on Christmas day for a funny little skit with Ciel-sensei, Neko-Arc, two very special guests.
Emotionless Girl: Hisui is rather perpetually blank faced and it isn't until late in one of the "far side" routes that Shiki realizes that Hisui has actually shown a wide variety of emotions such as embarrassment and anger, while her sister never seemed to deviate from that broad smile...
Enemy Within: Shiki loses control of himself to his assassin's instincts more than once until he learns to keep it under control, though this isn't really a distinct personality. In Ciel's route, he becomes possessed by Roa, who most certainly is.
Erotic Dream: In the game Arcueid sends her succubus dream familiar to cause this, as a 'reward' (who's in the dream is up to Shiki, though). The anime turns it into a brief nightmare instead.
Our first real hint of the kind of person Arcueid is comes after she's managed to recover from being killed by Shiki. She waits at the intersection until she spots him again, chases him, corners him... and then demands to know if he's sorry for what he did, and that she can only forgive him if he is.
Nero Chaos' on the other hand is him casually strolling into a hotel and simply eating everyone there via a horde of monstrous animals. Man, woman and child are all eaten alive without a scrap left.
Evil Eye: A large variety of these exist with the strongest ones being naturally occurring and impossible to reproduce artificially. Not all powers are impossible to reproduce, but those that are are always much weaker and of limited variety. While abilities other than the below exist in the Nasuverse, they do not appear in the main Tsukihime storyline or character material.
Shiki's has the Mystic Eyes of Death Perception, which are so incredibly rare that they are a legend even to those of Arcueid's stature. They allow him to cut along any lines of death that he sees and if he pierces a point of death, whatever he has stabbed dies or is destroyed. Things that have been cut will not heal.
Ciel has the Mystic Eyes of Whisper. Probably. These are an artificial type that any magus of sufficient skill can give themselves. They allow her to put someone into a mild hypnotic state where they will rationalize whatever information she gives them, though this is far from perfect.
Arcueid and Satsuki, like most vampires, possess the Mystic Eyes of Enchantment which allow them to dominate the wills of the weak minded.
Akira Seo possesses eyes that allow her to see possible futures, which is seen as more valuable than someone who can see what will definitely happen as it allows her to do something about it. Sometimes, however, she will foresee something that never occurs.
The serial killer from the Plus Disc allows him to see into the past, though he lacks context.
Roa, due to his multiple reincarnations, gained some sort of Mystic Eye ability that allows him to see the lines of life on living beings in the same place Shiki can see lines of death. This allows him to harvest said life.
The Nanaya clan had Mystic Eyes that allowed them to detect nonhumans. Nanaya Kiri could see this in the form of auras. Shiki may or may not be able to do this in addition to his more well known abilities.
Finally, Crimson Moon Brunestud has an unknown variety of Mystic Eyes classified as Rainbownote The Mystic Eyes of Death Perception are classified as blue, whatever that means which have an unclear effect.
Eye Scream: Ciel, in the manga puts one of her swords in Akiha's hand and stabs herself in the eye. Akiha's horrified reaction proves to Ciel that Akiha isn't a killer.
Evil Plan: You learn in the Far Side route that Kohaku manipulated everyone in the Tohno mansion towards their deaths for eight years, ever since Shiki took a knife to the chest for Akiha. And the most horrible part is that she did it to give her life a purpose.
Shiki is pretty much an amalgam of Ryougi Shiki and Mikiya Kokutou, the female and male leads of Kara No Kyoukai.
Akiha is an expy of Kokutou's little sister Azaka. The only big difference between them is the nature of their otherwise similar powers and that Azaka is Kokutou's real blood-related sister.
Kohaku is an expy of Asagami Fujino.
Fan Disservice: During one of the later routes, Shiki has a dream involving Kohaku or Hisui being raped. It is not arousing. On a more comedic note, the actual sex scenes are no better due to Nasu's questionable usage of metaphors. Let's just say he has a strange fondness for seafood.
Fights Like A Normal: While the Nanaya clan were all 'psychics'note People with inherent special abilities that are not magical in origin but rather some sort of genetic mutation for the most part their abilities were no more than the ability to sense non humans. Shiki's father Kiri, for example, was an amazing assassin, but his ability was just simple Aura Vision.
Flanderization: Anything outside of the original game is notorious for doing this, though most of them are only in joke scenarios. Arc's airheadedness and general silliness tend to dominate the serious aspects of her character and Ciel obsesses over curry with little mention of her actual work. Akiha's jealousy and self-consciousness over her small bust size both tend to get exaggeration while Kohaku's mischievousness, connivingness, and energy have more or less supplanted all other aspects of her character. Since Hisui is the quiet type, there's not much to exaggerate. The solution? Just add a bunch of ridiculous things relating to her character: Mech-Hisui, Dark Hisui Fist, Brainwashing, and that chair.note It's an eyesore.
Forgotten First Meeting: Shiki doesn't remember either of the twins at first. Can be traced back to Makihisa more or less stripping those memories from his brain. After completing the first set of routes, we learn that Shiki does have some very vague memories of the maids, but he can't remember their names or appearances very well, which is shown by having flashbacks leaving them nameless and in black and white, which helps hide which twin was which.
Forgotten Friend, New Foe: SHIKI to Shiki. Like with the twins, it can be traced back to Makihisa more or less stripping those memories from his brain.
Future Badass: The official side stories released have Shiki somehow becoming even more badass. His eyes have gone out of control, so he has to keep them bandaged and his previous physical limitations have been surpassed. He's taken on the name Satsujinki and spends his time hunting down and assassinating the Dead Apostle Ancestors. It gets even better.
Hard Drinking Party Girl: Akiha shows many of the characteristics under certain circumstances, shows a marked fondness for whiskey, and, to top it all off, holds her liquor surprisingly well.
Harem Genre: Eight girls confirmed, and maybe Len considering by preference she wants to sleep with him rather than get his blood, either of which work. Lampshaded by Arihiko who is frustrated at how suddenly no girls are interested in him yet Shiki has about... well, eight or nine hanging around him all the time. In the original game, however, this never really comes up. At most, Akiha gets jealous.
Heavy Sleeper: Shiki's managed to seriously alarm both Hisui and Arcueid with how deeply he sleeps. It occasionally looks like he's outright dead.
The Hecate Sisters: Arcueid as the beautiful and ditzy maiden, Ciel as the eccentric mother fighting off weight gain and Akiha as the bitter and sharp tongued crone.
Hidden Eyes: Shiki, in every image he appears in after the prologue of the original Tsukihime. His "Sensei," the magician Aoko Aozaki, has the Hidden Eyes whenever she appears until the game's final image. It's used for a plot twist in the Plus+Disk story "Mystic Eyes Alliance" that introduces Seo Akira and shows Shiki's character model for the first time.A killer posing as Shiki tricks Akira and the reader into thinking he is the real one, as Shiki's character model was still unknown at that point. At the end, we finally see the real sprite for Shiki and while they look similar, they're obviously quite different people.
Homoerotic Subtext: Neither Shiki nor Arihiko use Honorifics when talking to each other, but it's Shiki's habit of also referring to Arihiko by his first name that makes Akiha do a double take. Normally, that's either a sign of great intimacy or something girls do.
Immortality: One of the key themes is that death is an inescapable inevitability for everything, even things with some variety of practical immortality. It has been revealed in related works that even beings like the "deathless" Arcueid, Gaia (the planet), and everything/anything else will eventually die - they just exist with different concepts of death.
Informed Ability: Arc is supposed to be nigh-on to a Physical God, designed to be the greatest and most feared of all True Ancestors, four times as powerful as a Servant... according to backstory, anyway. Thanks to having to constantly suppress her Unstoppable Rage and suffering the Drama-Preserving Handicap of being killed torn to bits at the beginning of the story, however, for the majority of the story she's very weak. In Ciel's route, she manages to regain some strength due to spending less than she did in her own route meaning she fights, beats and 'kills' Ciel in about twenty seconds.
In Joke: Combined with Title Drop, one of Akiha's friends who appears in Kagetsu Tohya is named Tsukihime Souka. Her name would make her seem important, but she's completely mundane and only appears twice.
Interplay of Sex and Violence: The scene where Shiki sees Arcueid for the first time and is seized with an incredible urge to *** her (as the game puts it) which takes the ambiguity over what four letter word Shiki wants to do to her to the further possible extreme before he finally kills her. Many violent scenes are often written in a rather sexual manner and often have people actually sexually excited.
Intimate Healing: Synchronizers have the ability to share life force and power up others through "fluid exchange" typically via horizontal tango, though this is just the most powerful way. Notably, this is how Hisui and Kohaku save Shiki's life in their respective routes. More disturbingly, Makihisa and likely SHIKI took advantage of this ability by raping Kohaku repeatedly, for ''years'', in order to avoid inverting. Ciel also gets a sort of similar idea going on in her sex scene. Apparently, Roa's best way to get revenge on Shiki is to give him priapism until his dick falls off. Riiiiiight.
Ironic Echo: Arcueid likes to talk about what-ifs, Shiki doesn't. They reverse that little exchange when Shiki tries to give a dying Arcueid hope near the end of her route.
Japanese Sibling Terminology: Akiha always refers to Shiki as "Nii-san" to refer to Shiki and Hisui always refers to Kohaku as "Nee-san." When either of them use another term, it means Akiha's talking about her real older brother and It's actually Kohaku impersonating Hisui.
The Killer In Me: In the "Far Side" routes, Shiki thinks that he is the killer. In Akiha and Hisui's route, he's wrong. In Kohaku's, she drugs him into going out and committing murders, but he doesn't remember this.
Laser Guided Tykebomb: In the past, Arcueid was created from scratch as a living weapon directed at the demon lords and frequently had her memories erased. It was intended to allow her to develop normally after she was gone, but then things went wrong.
Last Of Their Kind: Arc is the last True Ancestor vampire, now avenging the slaughter of the others she accidentally enabled. And Tohno Shiki is the sole-surviving member of the Nanaya clan, a family of elite assassins who specialized in killing demons and demon-hybrids. Both are only hinted at in the anime.
Living Battery: The Synchronizers are living magical batteries that can accumulate and transfer life energy to other people
Love at First Punch: More like "Love at First Murder" between Arcueid and Shiki. He slices her to pieces, she spends the night reviving herself and the next day she tracks him down and introduces herself.
Love Triangle: Almost Ciel's entire route. In her Good Ending she's unable to score a complete 'victory' and gets pissed off at having to share her better ending.
Lethal Chef: Hisui cooks so badly it's considered poison. One doujin has Shiki trying to use his eyes to "destroy the badness".
Locked Out of the Loop: Shiki. Arcueid's about the most honest person he knows, though while she doesn't lie to him she doesn't want to talk about herself much.
Lowered Monster Difficulty: In the last fight of Kagetsu Tohya. In fact, it lowers specifically during the fight, as Shiki realizes he's survived Kouma's attacks beyond what he expected...or rather, because Shiki realizes it, and realizes that his growing confidence means his nightmare is becoming weaker.
Lotus-Eater Machine: During Ciel's path. Specifically, his near-death coma dream in Ciel's True ending. Also, the Kagetsu Tohya side story "Flower of Thanatos" though Shiki realizes he's trapped. And he's not happy. It also becomes clear early on in the main story that Kagetsu Tohya is one of these though it turns out that Len is actually doing it for herself as a chance to live for once.
Male Gaze: Even when Shiki's 'on-camera,' he's usually far removed from the center of the screen, or is even behind the girl.
Man Behind the Man: During Hisui's route, Kohaku at the end is revealed to have been behind SHIKI.
Marry Them All: Ciel's good end has Arcueid trying for a three way relationship. That or just plain stealing/seducing him away from her. Ciel is not amused. Shiki does not want to die.
May-December Romance: Despite being quite young, the "Eclipse" scene at the end implies that Shiki will probably die young due to his eyes.
Mayfly December Romance: Implied in Arcueid's good ending. Arcueid chooses to stay awake so she can be with Shiki, but Fridge Logic reduces the goodness of this ending, as Shiki is very mortal whereas Arcueid is a deathless vampire. Arcueid can't fix this through the obvious means, as it would make Shiki into a Dead Apostle, which essentially amounts to making him into another Nrvnqsr.
Meaningful Name: Surprisingly averted; Akiha's friend Souka Tsukihime doesn't have anything special about her at all and her name is just a joke by the game creators.
Meido: Kohaku and Hisui. Hisui calls Shiki "Shiki-sama" despite his efforts to convince her to be less formal.
Mind Rape: A Psychic Link with SHIKI causes him to either see SHIKI's actions or those of the vampire possessing him. Both are largely torturous and make Shiki think he's a psychotic killer.
Mind Screw: Hisui's route. About half of it is Shiki sick in bed, generally going completely insane.
"Melting wall. Solvable meaning. Self who can explain. Smoothness of changeable permeability. Transitioning time. Observation life and execution function. A pinky-less hand. Headless eyes. Rolling carpet. Once. Twice. Three times. 777 cages. Burst balloon. Unfulfillable promise. Unprotectable law. Death contract. Poison and honey. Red and afterbirth. Mercury lamp and bug light. Light refracting from countless dimensions. Swimming fish, singing at the ocean bottom. Tools, tools, tools. Towards endlessly reproducing stars without meaning, without will. Better than wishes. Another only me. Unraveling deep sea. Contradictory that appears from microscopic organisms. Detailed view of a quark. Rejection of everything. Formless form. An embryo within a hearse. I curse and celebrate their existence."
Multiple Endings: Arcueid, Ciel, Akiha, and Hisui each have two endings while Kohaku has one. There are also numerous "Dead Ends" for when you screw up a decision. Some routes have more pitfalls than others.
Mundane Utility: Shiki uses his Mystic Eyes to "kill" locks. Which is actually pretty cool, but also pretty mundane compared to killing vampires, entire hallways, and chunks of the Earth itself.
My Greatest Failure: Shiki is constantly pained by the fact he was unable to keep his promise with Satsuki, which caused her to be turned into a vampire that he had to kill.
Named Weapons: Shiki's knife, the Nanatsu-Yoru (Seven Nights) is actually not a named weapon at all. It's just his family name (Nanaya) being misread.
Near Rape Experience: In order to suppress his Nanaya side in Arcueid's route, Shiki manages to bury his desire to kill her, but doesn't gain real control of himself and almost rapes her instead.
Nigh Invulnerability: In a variety of ways, including regeneration, resurrection, and locally reversing time. Arcueid alludes to basically being able to simply tank most attacks.
Noodle Incident: In Kagetsu Tohya, Shiki occasionally refers to the haunted house his class did last year, in which he and his friend were responsible for something that resulted in their student government making an amendment that strictly prohibits tea kettle monsters, mushroom monsters, and any pot that uses the aforementioned things. The specifics are left up to the imagination.
Shiki: Yes, we did a haunted house my freshman year, too. Well, Arihiko did his part so ardently that we were forced to stop in the morning. (To himself):The Inuidake Children Kidnapping. It's an event that will forever remain in the annals of the student government.
If Shiki chooses to run away from Arcueid while she's sleeping in the hotel room, and then later returns, she unknowingly heaps further guilt on him by her dialogue revealing she'd never for a moment thought he'd abandoned her - she was just angry that he would do something so reckless as to move around town by himself.
Kohaku gets big one in her route, when she gives Shiki hallucinogenic drugs claiming its just something to help him sleep/relax, he takes them without second thought while saying things like how trustworthy she is or how he will now be able to sleep better - and she loses her perpetual smile for a moment.
Major plot point for most of the routes, if not all; rather chilling in Kohaku's when you realize that for once it wasn't any form of a dream, he really did go and kill people and even had a philosophical conversation with SHIKI while in a drug-induced quasi-Nanaya state.
Also in the Kagetsu Tohya story "Drinking, Dreaming Moon" which passively mentions Kohaku cleaning up the cups and sake bottle Shiki and SHIKI were drinking from during the dream...
Our Vampires Are Different: Like Blade, there's the natural species of vampires and the "infected humans" vampires. Arcueid's status as a True Ancestor (the former) exempts her from the rules that constrict the Dead Apostles (the latter) such as weakness to sunlight and the need to feed on humans to survive. She really does hate garlic though, but it seems to just be because she hates it. While Arcueid is the vampire we see most often, the other vampires we see aren't much like the classic image either. Arcueid herself complains in a couple of bad ends about Satsuki being the only "proper" vampire in the game. Side material indicates there are some really bizarre vampires out there.
Outdated Outfit: Kohaku's kimono and apron are very old-fashioned by Japanese standards. Paired with her bamboo broom, she could just as easily be placed in a Meiji-era work.
Pixellation: Per the Japanese standard for porn scenes.
Protectorate: Hisui is Kohaku's protectorate. Even without the mask breaking when Kohaku thinks Shiki might have done something to her she does not respond well, even if Shiki doesn't notice. Just imagine if he actually had done something.
Red Eyes, Take Warning: Straight: Noticing that Satsuki suddenly (though inconsistently) has red eyes is the first indicator that something is seriously wrong. On the other hand, Arcueid is pretty harmless to non-vampires; it's when her eyes turn gold you're in trouble. Red eyes are generally a sign of something being not quite human.
Reincarnation: The Big Bad Roa became a reincarnator as his own style of obtaining immortality with his mind/powers surfacing in one host after the other. His appearance/gender change freely with each appearance. Though it turns out that Roa is already mostly dead.
Revised Ending: The manga follows the True End to Arcueid's route, but adds in a bonus scene where with the help of Ciel Shiki tracks down the Castle Brunestud where Arcueid is intending to lock herself up and reunites with her. This is probably a combination of the fact that the True End is kind of depressing and also does not fit into established canon where Arcueid is still around and seemingly Shiki's canon love interest.
Right Behind Me: Shiki has shown active curiosity about girls' rooms on three separate occasions.
Akiha catches him off-guard in her room and glares him away.
In Kagetsu Tohya, Shiki invokes the trope while going through Ciel's clothes, and barely escapes. In a subversion, however, trying this with Arcueid's underwear drawer gets Shiki killed by a talking jaguar. Yes, really.
Also in Kagetsu Tohya, Akira definitely wants to keep her friendship with Shiki secret from his jealous sister, her upperclassman. After he suggests they meet up with Akiha at the school festival, she confesses this desire to him in stark terror. Irony, as it turns out, is a bitch.
(Akiha starts dragging Akira away for (implied) torture) Akira: "Hiiiiing! Tohno-senpai is horrible! A devil! Not even human!" The extreme fear must have gotten into her head and messed up her mind completely. Akiha: "Oh? That's unexpected. You only just now notice it after having been at my side for two years?"
Right Through His Pants: With the exception of Akiha's H-scene, Shiki has an odd aversion to taking off his pants. Also, a rare gender inversion: Kohaku proves that it is possible to have sex while wearing a kimono.
Running Gag: A rather minor one in Arcueid's route - Shiki will say or want to say something and Arcueid will complain that she can't hear him and so lean in closer, only for him to yell what he wants to say into her ears as loud as possible.
Schrodinger's Gun: The appearance, motivation, and personality of the Big Bad changes completely depending on whether you're on a Near Side or Far Side route even though they're the same person. Sort of.
Science Destroys Magic: While Tsukihime doesn't focus on magic very much, it establishes the idea that where magic and fantasy was once powerful, it now has to hide from society at large or risk destruction.
In the manga, Ciel tests whether Akiha has it in her to be a murderer by threatening her and her brother and then fighting her to the death. What Akiha doesn't know is that Ciel cannot be (permanently) killed/injured, so Ciel is free to test Akiha's power with impunity and make Akiha stab her in the face. Akiha's horror showed that she wasn't a killer.
Ciel also tries this in the original Visual Novel with Shiki, who is afraid that he is the murderer who has been stalking the streets in his dreams. However, Ciel's testing of Shiki was a bit... flawed. The idea was to prove that he was not the Ax Crazy bloodthirsty killer responsible for all the serial murders, which was correct, except the way she went about it and the wrong assumptions she made about him ensured that things would be very likely to Go Horribly Wrong. Mostly, the charade relies on the fact that he is not a born killernote Yes he is, though at least humans like her are normally safe, he wouldn't randomly kill people while motivated by base bloodlustnote That's how the other major scenario starts and he wouldn't kill someone, least of all a classmate, even when put in a do-or-die situationnote He did just that a couple of days ago. Oh, and that she is unkillable anyhow, so even if she were wrong about him, he couldn't kill hernote Oh yes he can.
Shadow Pin: Ciel can use her Black Keys to do this.
Shout Out: There are several references to Gunparade Marchnote the heroine of that anime is mentioned in one of the concept arts for Sacchin in the Plus Disc and to Hajime no Ippo in the comedy fight between Ciel and Arcueid in Kagetsu Tohya.
Once per route. In Arcueid's and Ciel's paths, Shiki does it against Nrvnqsr Chaos; in Akiha's path, he does it against SHIKI. In Hisui's and Kohaku's paths, however, Akiha of all people pulls off the Walk (once against SHIKI, and once against Shiki).
In the manga, Shiki pulls it off once more against Roa. That, alongside the fact that Shiki is successfully killing Roa's magic, utterly terrifies Roa.
Supernatural Elite: The True Ancestors don't exactly have a proper hierarchy, but the highest-ranking of the True Ancestors are the ones closest to manifesting the Crimson Moon — Arcueid and Altrouge Brunestud are considered the princesses of the True Ancestors, though the latter can't actually do it and has her title for other strengths she possesses.
Suspiciously Vague Age: So close to an aversion you almost want to hand it to them, but you can't. Kohaku and Hisui don't really have a defined age or grade level, Arcueid is hundreds of years old, Ciel is about 25 but looks younger. Len's age is confirmed at being in the Arcueid tier... but then you get to Shiki himself and Akiha, and the aversion falls flat.
Sweater Girl: Arcueid. Because not all vampires have to wear black leather or skimpy clothing to be sexy.
Much of the reason Akiha has Kohaku attend to her as her maid is to try and treat her well and show her friendship, so as to atone for her father's abuse. She's rather rude to her sometimes in spite of that, but Akiha's short tempered with everybody. This trope also comes into play more explicitly in Kohaku's route, when Kohaku and Hisui switch places so that Kohaku is Shiki's maid due to their growing relationship.
Hisui also has some elements of this with Shiki due to the fact that she often helps Shiki more than is strictly necessary, and has a crush on him that's more or less obvious depending on the route. In Kagetsu Tohya, she mentions how she'd really like to follow him outside the mansion when he moves out and continue serving him there.
Superpowered Evil Side: Nanaya, the amoral super-assassin who reallyenjoys what he does. Luckily he only targets monsters. Shiki's own perception of this side is much harsher, however, turning him into a sadistic murderer.
Three-Way Sex: In Kagetsu Tohya is the unlockable side story 'Flower of Thanatos', where Shiki can have a passionate sex with Hisui and Kohaku. Shiki is really not enjoying it, though, since the only way this could ever possibly happen would be in a hellish world of seclusion.
Through the Eyes of Madness: Not present in every route, but Shiki's hold on sanity gets pretty strained at times, to say the least, and the story is written from his perspective.
First Satsuki is killed by the monster Arcueid is chasing, but since she had such staggering latent magical potential she quickly revived into a full vampire where her new condition is putting her through horrible agony and forcing her to drink blood to stave it off. She's still semi aware and accepting of her previous life, meaning she's quite mentally twisted as well.
We also find out as time goes on that even SHIKI is another case of this. Due to Roa possessing him and his nature already being quite prone to going berserk he went insane at a young age and killed his best friend. Akiha was able to undo this, but she couldn't salvage her brother. He gets some emotional resolution in a Kagetsu Tohya sidestory and it's clear that if it weren't for circumstances completely outside his control he'd be a really nice guy.
In Kagetsu Tohya's non canon short story "Dawn" Nero Chaos seems to have revived but it's just the girl that he ate at the park right before being killed by Shiki. She just wants to see her sister one last time and is dying anyway.
Tranquil Fury: Shiki radiates this during his confrontation with Roa after Arcueid's death. Or rather, his eyes do, which Roa finds off-putting.
Traumatic Haircut: Altrouge did this to Arcueid a long time ago, as shown in one of the stories on Tsukihime Plus Disk. Merem Solomon and Gransurg Blackmore intend to get her back for this during the ritual in the Dark Six. Ironically, Arc herself doesn't seem to care.
Kohaku disguises herself as Hisui at least once, depending on the route. Pay attention to the eyes and the way she speaks of others and you'll catch on.
In the eight-year period Shiki's been away, Hisui and Kohaku have switched their cheerful and emotionless personas, respectively, with the result that Shiki doesn't remember which is which.
Uncanny Valley Girl: Though she doesn't seem to be at first, the maid Kohaku is in fact a deeply disturbed individual that is just rather good at hiding it. She doesn't seem entirely aware of all she needs to hide, however, resulting in scenes like cutting her hand open and not reacting to it at all.
Unexplained Recovery: Shiki, in a Kagetsu Tohya side-story that's a direct follow-up to Akiha's True Ending. All we know is that Ciel was involved.
Most of Arcueid's power is put towards containing this. In Ciel's route, Arcueid loses control, with terrifying results.
In some of the far side routes due to his connection with SHIKI Shiki finds his temper flaring and becoming uncontrollable.
Utsuge: Most of the "True Ends" are rather sad. Akiha's Normal End is even worse.
Vaporware: Tsukihime 2: The Dark Six. It got a No Fourth Wall trailer in Kagetsu Tohya and three prologue chapters have floated around the internet forever. Not a single other thing is known about it, never mind a release date. The Tsukihime remake used to be this, but it was finally officially announced at the end of the Tsukihime manga.
Wham Episode: Hisui's True Ending, especially if you're playing through the routes in the preferred order of Arcueid -> Ciel -> Akiha -> Hisui -> Kohaku, will put a new spin on much of the plot in every other route up to that point.
Wham Line: "Yes. Let's talk about your beloved childhood, Shiki-sama."
White-Haired Pretty Boy: In the Far Side of the Moon routes, the villain's one of these and wears a kimono; surprisingly different from his more Western Near Side of the Moon appearance.
The in-game description cites the power's name from a hypothetical jar with one hundred marbles, one white, the rest black. A Marble Phantasm is the ability to always pick the white one despite only having a 1% chance normally. A Reality Marble (shown in Fate/stay night) would change all the marbles in the jar to white.
Demonstrated once in the original game. By altering probability in ways that would make a chaos theorist weep, causing blades of wind to form in Roa's exact location, utterly destroying him down to the ankles. This was using the bare minimum of her power since it was all she actually had at the moment. Unfortunately, it didn't kill him.
The Worf Effect: In Kagetsu Tohya, Nanaya manifests as Shiki's nightmare of himself becoming a true murderer. Shiki never wins a fight against Nanaya in the game, though as he realizes this is because he's not fighting with all his true ability. Turns out Shiki has an even worse nightmare, of Kishima Kouma, the man who killed his father. Guess who's head that guy's holding here◊.