She is the older of the two twin maids in the Tohno mansion. Her name, Kohaku, is the Japanese word for amber, referring to her eye color.
Kohaku was a member of a branch family of the Fujou clan, but was brought with her sister Hisui to live in the Tohno mansion, because the Fujou clan had a special power of giving others energy. Makihisa Tohno needed this ability in order to keep control of his body. This transfer of energy is strongest though the means of sexual intercourse.
Due to it, as a child she was constantly raped by Makihisa, and unlike the other children, she had to watch them from afar as they played together. Just before Shiki Tohno leaves the mansion to live with the Arima family, Kohaku gives him her favorite ribbon and makes him promise to return it, indirectly begging for him to return.
Some time later, Makihisa decided to give more freedom to Kohaku, but in order to do it, she had to take care of an imprisoned SHIKI (who was imprisoned due to the Shiki incident and the fact Makihisa did not want to kill his son). However, some time later, due to having to keep control of his body, just like his father; SHIKI raped Kohaku. This drove her further into despair and decided to get revenge on the Tohno family. To do it, she twisted and brainwashed SHIKI with her medicinal herbs, all for the sake of her revenge. Some time later, Akiha and Hisui learned of Makihisa's sin against Kohaku, and it depressed them greatly. Akiha freed Kohaku from Makihisa and she became a normal servant. But Hisui was still depressed so Kohaku, seeing her sister's free enthusiasm falter for her sake, promises Hisui that she will "take on her role" until she was cheerful again. Ironically, it is because of those words that Hisui is unable to return to her old self.
Due to her intervention, SHIKI killed Makihisa, which was the reason why Shiki returned to the Tohno mansion.
Kohaku has short red hair, like her sister Hisui. She wears a blue ribbon at the back of her head and wears a brown Japanese kimono.
Kohaku is able to pose as Hisui during Tsukihime through the use of colored contacts and by drugging her with sleeping pills to keep her out of sight. Kohaku also gives clues as to the difference between them through her speech, as Hisui will always say elder sister (姉さん, neesan?), while Kohaku always says sister (姉, ane?).
Kohaku is always seen to be smiling and cheerful, being especially gifted with medicine which she learned from Jinan Sougen. She has a habit of breaking many (and valuable) objects when cleaning indoors. Though she always states that it was not intended, some characters, like Akiha, seems to think otherwise.
However, all of it is an act. In truth, Kohaku's smile is empty, as she was mentally scarred and traumatized at a young age due to constantly being raped by Makihisa. Eventually, she stopped feeling emotions, and put up a false smile as well as a cheerful demeanor. In most of the routes of Tsukihime, she continues this facade after the routes end. However, in her own route, she manages to forgive the Tohno family, and eventually truly becomes a cheerful girl.
She claims to have hated Shiki for the silent connection they shared as children (watching one another but never meeting), but it is revealed that she is actually in love with him, and it is in part why she wanted to take on Hisui's role in the first place. Kohaku simply wanted to innocently love the boy named Tohno Shiki, just as Hisui did as a young girl.
Kohaku merely appears as a supportive character, who is a cheerful maid who is very close to Akiha.
In the anime, based on that route, Kohaku has a secondary role and she remains as Akiha's cheerful maid. Despite Akiha's cold demeanor towards Shiki, Kohaku knows that in fact Akiha loves her brother very much. After Akiha starts succumbing to her demon blood, she helps her by letting Akiha suck the blood from her breast. Despite Akiha's desire not to involve Shiki in the secrets of their childhood and the Tohno family, Kohaku's (with the help of Hisui) provide Shiki with information about the family at the right moment in order to make him discover who he is.
Because the events of Arcueid and Ciel, keep Shiki away from the Tohno mansion, Kohaku simply appears as a cheerful maid and a supportive character. Near the end of the route, she is mercilessly injured and raped by Shiki, whose personality was overtaken by Roa. This causes him to escape from the mansion, afraid that he will be unable to resist the urge to kill.
In Akiha's route, she is loyal and devoted to her and helps her after she slowly starts to succumb to her Tohno blood, even letting her to suck the blood from her breasts (something that also happens in Kohaku and Hisui's routes). In Akiha's Normal Ending, Shiki mentions that Kohaku still takes care of Akiha even after she has become a mindless monster. In Akiha's True Ending, after Shiki sacrifices his life to save Akiha, Kohaku and Hisui try to convince her that Shiki is not dead, which she later realizes.
“"That's right. All of it was something I wished would happen, Shiki-san."”
In Hisui's route Kohaku plays a much more crucial role. It is eventually revealed that all of the bad things that were happening were indirectly because of her and that she had manipulated everyone in the Tohno mansion over the course of the previous eight years in order to give her life purpose and fulfill her revenge against Tohno family. During the route she begins feeding Shiki drugs, which causes him to question his sanity. She even disguises herself as Hisui. This results in Shiki raping her while she is impersonating her sister. Nevertheless, she continues her manipulations. After the successful fulfillment of her revenge, she decides to kill herself.
In Hisui's True Ending, after Akiha and SHIKI die, she reveals everything to Shiki and commits suicide by stabbing herself in the chest to end her "doll's existence". It is revealed that she feels guilty about letting Akiha die and did not kill Shiki because he gave Kohaku some sort of hope eight years ago, just by looking at her through the window she was trapped in.
In Hisui's Good Ending, she protects Akiha from SHIKI at the last second. Because of this, she feels that she failed to complete her revenge. She then tries to commit suicide by ingesting poison instead of stabbing herself. She is saved by Shiki, who cuts the "lines" of the poison within her. She is left in a coma, but she soon wakes up and seems to have lost her memory (it is implied she did it on purpose). Forgetting her past and what she has done, Kohaku is renamed "Nanaya" by Hisui, and returns as a peaceful maid to the Tohno Mansion.
“"Shiki-san...why did you have to return?"”
When Shiki returns to the Tohno house, he is greeted by Kohaku. Like in Hisui's route, he wants to return the ribbon given to him by the quiet girl who watched him in the past, mistaking that girl for Hisui. After drinking all night at his welcome party, Shiki goes outside for some fresh air and to cool off. Where he runs into Kohaku.They begin to talk to one another, and eventually Kohaku warns Shiki that he will only find suffering in the Tohno house and wonders aloud why he had to return. In response to this, Shiki tells her about about the promise he made to the quiet girl, and that it was a major reason he returned. Kohaku's face brightened a little when he mentioned this, but was quickly heartbroken when she learned that Shiki thought that girl for Hisui.
Later in the route, after noticing that Shiki is intrigued about the mysteries about his past, Akiha tracks down and kills SHIKI with Kohaku's help before Shiki even begins to have dreams of him.
After a slip of the tongue, Hisui reveals to Shiki that Kohaku was the girl who gave him the ribbon in their past. Due to SHIKI's ability of immortality and the nature of Akiha's powers, he transfers the burden of his madness caused by the inversion impulse of his Tohno blood to her when Akiha absorbed his energy to kill him. Because of this, Akiha began to slowly succumb to the Tohno blood, despite originally being able to control it by synchronizing with Kohaku. But now, it wasn't enough, since she now had SHIKI's bloodlust. As a result, she began hunting for victims on the streets at night in SHIKI's place because she can't control herself, with only Kohaku being aware of it.
Kohaku hints at this change which leads to Shiki confronting Akiha face to face, which nearly kills him due to Akiha taking back the power she shared with him. According to her, the only way to stop it is by reciprocating Akiha's feelings for Shiki. However, Shiki refused to do such thing because he loved Kohaku instead. He returns the ribbon to her in that moment, telling a lie to her that he realised when Hisui had no recollection of the event. In response, Kohaku began to cry, and decided not to continue with her revenge against the Tohno family. She offers her ability to Synchronize with Shiki so that he can stop Akiha, and the two make love as a result. However, Kohaku tricks him into swallowing a sedative so that she could go confront Akiha by herself in order to atone for her past actions. After coming to, Shiki is able to resist the lingering effects of drug by cutting into his own nail, and eventually follows her to the school.
There, Shiki finds Kohaku's body tied to the wall by Akiha's hair. Akiha tells Shiki that the Tohno family had severely wronged Kohaku, and that everyone, including him, were all just pawns in Kohaku's plot for revenge. Shiki, however, tells Akiha that he loves Kohaku no matter what she has done, prompting Akiha to attack Kohaku. Shiki is devastated by this and retaliates against Akiha, but he ultimately couldn't bring himself to kill his sister. At that moment, Kohaku appears, completely unharmed, telling Akiha to stop because she held no resentment towards her, and that she had already forgiven the Tohno family. Akiha realizes that the reason Kohaku survived was because she subconciously held back because she ultimately still liked her.Kohaku is the only character with just one ending, which is also her True Ending. In it, she leaves the Tohno mansion after Akiha began drinking blood packs, and goes to work in another mansion of a branch of the Tohno family, but she returns to the Tohno mansion every weekend to visit. She eventually sends Shiki a letter telling him to come to Nagano during his summer break, and they meet up with one another in the Nanaya forest where Shiki lived in his childhood, surrounded by a field of sunflowers.
“"It's needle time!"”
—Kagetsu Tohya In Kagetsu Tohya her plotting manipulative personality is comically exaggerated. She is apparently also a mad scientist. If the player makes a bad choice, sometimes Kohaku would imprison Shiki in the same place SHIKI used to live in order to test her drugs on him. However, Kagetsu Tohya is just Shiki's dream, so she does not act as the real Kohaku would.
In The Tohno Family Con Game, she organizes a game of tag between all the characters, but in the end she manipulates everything so she can win (by dressing herself as Hisui).
In the Flower of Thanatos side story, which takes place in an artificial dream world, she and Hisui live together with Shiki in the isolated Tohno Mansion, where they humbly serve him by fulfilling his every wish. Shiki gradually grows bored of this and starts to seek escape from recurring stereotype of this world. Because of this Shiki will start even periodically raping her and Hisui but without any satisfying result. In the end in order to permanently change something he comes to the final choice between them. Depending on this choice then spends a night of passion with one of them, or both. If Shiki spends the night with both then Kohaku and Hisui gradually lose all their differences and becomes mirror-like couple, on which he's no longer able to recognize who is who. That finally allows him love them truly equally and accept artificial world as their personal paradise.
Kohaku has a number of roles in Carnival Phantasm as one of the heroines of Tsukihime. Kohaku's scheming and plotting personality is comically exaggerated as does so her loyalty towards Akiha. She is always seen plotting against Shiki and company for her own amusement. She also supports Akiha's relationship with Shiki.
In Fate/kaleid liner PRISMA☆ILLYA 2wei!, the eleventh of the manga and the seventh episode of the anime, when Irisviel von Einzbern talks about the power of a big sister, Kohaku makes a cameo appearance alongside Stheno, Euryale and Touko to illustrate Irisviel's remarks.
Kohaku normally lacks any sort of combat capabilities. She is a Synchronizer, which allows her to transfer energy through the exchange of bodily fluids. While it can be done with those of the same sex through a transfer of blood, it is most effective through sexual intercourse with someone of the opposite gender. She is a skilled pharmacist.
Kohaku is in charge of managing the Tohno mansion's gardens, but she also cultivates her own secret garden as a hobby, like her own personal Mekong Delta. Though originally it was created for the sake of making medicine, due to the influence of the Tatari there was an outbreak of strange monsters. It goes by the name of Psycho Garden. This garden is also where Kohaku's various chemicals magical drugs are manufactured, the source of both Makikyuu X and Tonamin Z. Thanks to a collaboration with Sion, you can expect the development of even more devilish drugs in the future. She has a technique called I Tried My Best To Raise This! (こんなん育ててみました?) where Kohaku whips out various bizarre plants such as fireball-shooting Piranha Plants to aid her. Magical Onslaught (マジカル攻撃?) is a name for all the dubious techniques used by Kohaku. Though they're called things like Magical Attack and Magical Missile, no matter how you look at them they're chemical weapons. Unsealed Kohaku Kick (開打靠靭琥珀脚, "Unsealed Amber Kick"?) is Kohaku's Arc Drive. After changing into Chinese clothes, she unleashes a vaguely familiar series of techniques. During Blood Heat even more hits are added to the combination, but since this rampaging style is too violent there's a real chance she'll be fired after using it. The inspiration for this technique was Kagetsu Tohya, when Kohaku came to Shiki's school festival and wore a Chinese silk dress in his class's event.
 Tsukihime Dokuhon PlusPeriod - TSUKIHIME Dictionary: Kohaku [Person's name], p.179
Kohaku [Person's name]
A sub-heroine in Tsukihime. A servant working at the Tohno mansion. Sympath.
An energetic girl, that always sports a bright, unwavering smile. In the story, she was the servant assigned to Akiha, and was in charge of cooking, tending to the gardens, and managing the finances of the estate.
She has a natural cheerfulness about her, and just spending time with her is relaxing. On the other hand, she also has an extremely cool-headed and objective point of view – though she isn't even aware of it herself.
She was an orphan taken in by Tohno Makihisa together with Hisui, and spent her days confined in Makihisa's room. Then, around the time that Akiha entered her second year of middle school – after Shiki was put up for adoption – she found out about Kohaku's relationship with Makihisa and made her a normal servant working on the mansion grounds.
As a character, she represents "the lower ruling the higher".
Supposed to have been a sub-character to the bitter end, but could end up being the most popular of all if we're not careful… is what the staff thought. Wait, that's not right, hasn't there always been blatant favoritism?
In reality, when development first started there wasn't a route planned for Kohaku at all. What changed that, you ask? Well, after we released the Half-moon edition we read through the player feedback, and the one thing that almost everybody mentioned was that Kohaku needed a route too. So we caved to pressure and tacked it on at the very end.
Although she was a tragic heroine in Tsukihime itself, ever since then she's just been running around letting off steam.
In Kagetsu Tohya, she gathered popularity as a mischievous housekeeper, and showed the first signs of her budding talent as a mad chemist. Her exploits included building a secret room in the Tohno mansion's basement, wearing a hood and calling herself a magical girl, and even taking part in a bad end involving anesthetic drugs.
In Melty Blood, since she's more-or-less the Kohaku from Kagetsu Tohya and not the one from Tsukihime, her magical-ness received an upgrade. Though the unbalanced Kohaku is nice, the carefree Kohaku from Melty that does as she pleases is pretty nice too, don't you think?
…This is a digression, but apparently there are a lot of users that have been completely defeated by Kohaku's voice in Melty Blood. In fact, even the scenario writer was eviscerated.
 Melty Blood Act Cadenza PS2 Manual - Dictionary: Kohaku [Person's name], p.057
Kohaku [Person's name]
The older of the twin sisters working as servants in the Tohno mansion.
An energetic girl, that always sports a bright, unwavering smile. In Tsukihime, she was the servant assigned to Akiha, and was in charge of cooking, tending to the gardens, and managing the finances of the estate.
In contrast to her natural cheerfulness, she also has an extremely cool-headed and objective point of view that even she herself is not aware of.
She was an orphan brought in to the Tohno mansion together with Hisui. She has the bad habit of teasing her master, Akiha, even as she looks after her.
Furthermore, she is a skilled pharmacist, and often lends her aid to the anemia-prone Shiki. Though she is indeed well-versed in strange medicines due to her job, that fact was exaggerated by the Tatari, leading to her appearance as the extremely mysterious Magical Doctor Kohaku in Melty Blood.
また薬剤師でもあり、貧血がちな志貴をサポートしている。職業柄妖しげな薬にも精通しているのだが、それがタタリによって拡大解釈 され、MELTY BLOODでは世にも不思議なマジカルドクターとして活躍することに。
- ↑ Tsukihime PLUS-DISC - Geccha
 Tsukihime Dokuhon PlusPeriod - TSUKIHIME Dictionary: Psycho Garden [Place name], p.179
Psycho Garden [Place name]
Kohaku's own personal Mekong Delta. Made for Kohaku, by Kohaku. The botanical gardens in the Tohno mansion's back yard.
This is the source of both Makikyuu X and Tonamin Z.
It seems that recently even fireball-shooting Piranha Plants have taken root here.
Thanks to a collaboration with Sion, you can expect the development of even more devilish drugs in the future.
It's the advent of next-century biotechnology.
 Melty Blood Act Cadenza PS2 Manual - Dictionary: I Tried My Best To Raise This! [Technique name], p.056
I Tried My Best To Raise This! [Technique name]
The name of the technique where Kohaku whips out various bizarre plants.
Kohaku is in charge of managing the Tohno mansion's gardens, but she also cultivates her own secret garden as a hobby. Though originally it was created for the sake of making medicine, due to the influence of the Tatari there was an outbreak of strange monsters. It goes by the name of Kohaku's Psycho Garden.
Incidentally, this garden is also where Kohaku's various chemicals magical drugs are manufactured.
 Melty Blood Act Cadenza PS2 Manual - Dictionary: Magical Onslaught [Technique name], p.049
Magical Onslaught [Technique name]
A name for all the dubious techniques used by Kohaku.
Though they're called things like Magical Attack and Magical Missile, no matter how you look at them they're chemical weapons. It just goes to show, there's nothing good about the "magical" stuff in Melty Blood.
If the series continues, chances are even more magical armaments will make their appearance. There might even be a magic wand equipped with a dangerous and crafty artificial intelligence…
 Melty Blood Act Cadenza PS2 Manual - Dictionary: Unsealed Kohaku Kick [Technique name], p.058
Unsealed Amber Kick [Technique name]
Kohaku's Arc Drive. After changing into Chinese clothes, she unleashes a vaguely familiar series of techniques. The mock China feeling here is out of this world.
During Blood Heat even more hits are added to the combination, but since this rampaging style is too violent there's a real chance she'll be fired after using it… maybe. Sorry, Kohaku.
The inspiration for this technique was Kagetsu Tohya, when Kohaku came to Shiki's school festival and wore a Chinese silk dress in his class's event.
|Shiki Tohno • Arcueid Brunestud • Ciel • Akiha Tohno • Hisui • Kohaku • Len • Michael Roa Valdamjong|
|Arihiko Inui • Aoko Aozaki • Barthomeloi Lorelei • Crimson Moon • Gransurg Blackmore • Kouma Kishima • Merem Solomon • Mr. Dawn • Narbareck • Nanako • Noel • Nrvnqsr Chaos • Satsuki Yumizuka • Shiki Nanaya • SHIKI Tohno|
|Akemi Yamase • Akira Seo • Brainwashing-Detective • Caubac Alcatraz • Curry de Marche • Forte • Fake Shiki • Hanei Misawa • Ichiko Inui • Keiko Arima • Kiri Nanaya • Magical Amber • Maiko Yamase • Makihisa Tohno • Master Panda • Mecha-Shiki • Neco-Arc Bubbles • Neco-Arc Destiny • Neco-Arc Evolution • Phantas-Moon • Sougen Jinan • Souka Tsukihime •|
|Melty Blood characters|
|Miyako Arima • Dust of Osiris • Mech-Hisui • Neco-Arc • Neco-Arc Chaos • Night of Wallachia • Riesbyfe Stridberg • Shiki Ryougi • Sion Eltnam Atlasia • White Len|