Kohaku

Kohaku (琥珀) is one of the five heroines of Tsukihime. Her character image song is Yawaraka na Kizuato (やわらかな傷痕), performed by Cocco.

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.

Background
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 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.

Personality
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.

She claims to hate 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.

Appearance
Kohaku has short red hair, like her sister. She wears a blue ribbon at the back of her head and wears a brown Japanese kimono.

Arcueid and Ciel's routes
Because the events of Arcueid and Ciel, keep Shiki away from the Tohno mansion, Kohaku simply appears as a cheerful maid.

Hisui's route
It is eventually revealed that all of the bad things that were happening was indirectly because of her and that she manipulated everyone in the Tohno mansion towards their deaths for eight years in order to give her life a purpose. After succeeding in SHIKI killing Makihisa and Shiki killing SHIKI, she decides to kills herself after getting her revenge aganst them.

In Hisui's True Ending, after revealing everything to Shiki, Kohaku commits suicide by stabbing herself in the chest to end her "doll's existence". It is revealed that she 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 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.

Kohaku's route
If Shiki is able to recognize that Kohaku is the girl who gave him the ribbon in ther past and returns it to her, despite the twins switched attitudes, Kohaku decides not to continue with her revenge. She is the only character with only one ending, which is also her True Ending, in which she decides to forget her past, and goes with Shiki to the Nanaya forest as she is seen smiling in a field of sunflowers.

Carnival Phantasm
In Episode 2, Kohaku convinces Akiha and the girls to have a volleyball match in order to get Shiki. In Episode 10 she uses her special drugs to revert Akiha's personality to one of a 4-year old. Later she creates stories based on Hisui's detective persona with comical results. Kohaku does not hold any interest in Shiki, because she wants him to end up with Akiha. Kohaku's scheming personality is exaggerated, to the point her actions should be considered as trolling. In Episode 12. she is one of Shiki's dates, although he barely spends time with her because Shiki convinced her that he was trapped in one of her experiments. She and Hisui finally appear at the Ahnenerbe party together with Sella and Leysritt.

Abilities
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.

During Melty Blood, under the influence of Night of Wallachia, White Len, or Dust of Osiris, she gains the ability to create lots of mechas, such as Mecha Hisui and Mecha Shiki.