; : :The main heroine of the story. Kuro is depicted in a black coat and a wide-brimmed black hat with dark blue hair and hazel eyes, seen carrying around a large coffin. Before she was cursed, her name was 'Sunya' (derived from the Sanskrit word for "state of nothingness") but is referred to as 'Kuro' (Japanese word for black) after finding Nijuku and Sanju. Kuro found her former name to be unfitting with her cursed state because it was lady like and feminine. Personality-wise, she is calm and collective, and takes the role as Nijuku and Sanju's guardian. She is searching for the witch who cursed her and her friend, Sen. Her curse isn't well described at first, but it is made known early on that she wears bandages beneath her clothes in order to help slow the effects, and that it colors her skin black. Whether this coloring penetrates into her internal organs is debatable, but in the second volume, another girl a nearly identical curse is found in a flashback, whose body was dissolving where the black has taken hold. It is revealed that Kuro's curse worsens whenever she feels a strong emotion. However, the part of Kuro's curse that set it apart from that of other individuals is that she is unable to die. Hifumi took that upon their first meeting to help "complete" herself. Several times other people have attempted to murder Kuro, but each time the weapon they are wielding will malfunction, killing them instead. ; : :Kuro's friend, long-time companion and teacher. Sen, although very snarky as well as a womanizer, is very knowledgeable and wise. He was cursed to take the form of 1,000 bats, which he can seemingly control to a degree, although occasionally they do wander off or go missing. His name is a play on words, as he was Kuro's teacher (Sensei), and was then cursed to split apart into 1,000 bats. He can be accurately portrayed as the opposite of Kuro, who tends to be reserved and straightforward, while Sen is eccentric and speaks with
sarcasm. In the third volume of the manga, his curse was lifted for one night due to the "stained moon", hinting at his true from. Before being cursed by Hifumi, Sen was the middle son of feudal lord. He was seen as outlandish loner and lived in a mansion full of books, which caused rumors in the town to spread before Kuro's arrival that he was a maniac and/or monster of sorts. ; : :A little girl who is found with her sister, Sanju, by Kuro. Both Sanju and Nijuku show shape-shifting abilities as well as other supernatural traits, such as draining color from the environment and applying it to other objects or creatures and being able to change their size at will. Both Nijuku and Sanju are usually depicted with cat-ears and a tail. Nijuku's ears and tail are black, due to her trying to take some of Kuro's black coloring, which comes from her curse. Sanju and Nijuku were the professor's first successful
homunculi. Never being outside of the laboratory in which they were manufactured, the sisters are both learning about the world around them. Nijuku is the older twin, and is more gentle and level-headed than Sanju. Either way, both of them are very energetic and curious about everything. ; : :The sister of Nijuku, found by Kuro. She is younger as well as very emotional. Sanju tends to act impulsively, and disliked Kuro at first and tried to run away to find the professor, whom she assumed to be alive. After she warmed up to her, Sanju affectionately nicknames Kuro "Kuro-cha". Although Sanju means well, dislike her because she is rough with them as she does not understand that they can feel pain. This results in the death of a village child's kitten on her account. ; :A man who strived to create life as he was never happy with anything as a child, seeing all creation as dull, lifeless or "gray". The professor's real name is unknown. He states that fundamental issue is that he is in the world that God created, so no matter what materials are combined, the outcome will be "gray" as well. It is possible that he has
depression as well as
synesthesia. This apathetic outlook on life changes when he meets a woman whose aura he perceives as "black". The Professor then combines this woman and her two sisters in a vial, resulting in "Hifumi", the witch that cursed Kuro and Sen. The youngest sister was Kuro's mother. He also experimented with two dying girls and two kittens, resulting in Sanju and Nijuku. These were The professor's only successful humanoid creations. It is implied that one of his failed experiments ended up killing him, as he was found dead when Kuro arrived, rescuing the twins. ==Media==