Appearance: Shikaku is a beautiful young girl with long, reddish straight hair who enjoys wearing neat, school-uniform-style clothing. Her eyes are calm and give off a cold impression, to the point where no emotion can be felt. In the animation, Kana Hanazawa's calm yet chilling voice was added to maximize the character's mystery. Characteristics and Personality: Shikaku grew up suffering from severe abuse and gaslighting from her parents, who told her she was less than a dog. As a result, she has become a 'wasteland of emotion,' a human who completely lacks self-esteem and finds her value only in carrying out the orders (requests) of others. As a legendary killer, she possesses overwhelming physical abilities and killing techniques, but she is ignorant of how to love herself or feel human emotions. Through her meeting with Yuguel, she experiences a change in emotion for the first time in her life, moving by 'will, not by command.'

Appearance: Yuguel is a gentlemanly man in a clean, sophisticated suit, looking as if the 3,500 years he has lived mean nothing. As a vampire, he has pale skin and exudes an intellectual atmosphere, showing the boldness to plan his own death regardless of the eyes around him. In the animation, Tomokazu Sugita's characteristic sly yet deep acting was added to perfectly depict the boredom of an immortal who has become detached from life. Characteristics and Personality: He is a perfect immortal who does not die no matter what attack he receives. Having tasted all the pleasures of the world over his long life, he feels extreme boredom with existence, and his only wish is simply 'to die.' Therefore, he spends a large sum of money to commission the best killer, Shikaku, to kill him. However, he survives perfectly even after receiving all of Shikaku's fatal attacks, and instead, he begins to feel a strange affection and interest in Shikaku during the process. He is an ironic character—a man who wants to die but feels sympathy and liking for the one trying to kill him.