Male 16 years old Asa's twin brother Child of the Night The 'Night' twin of the pair that divides night and day Tsugai: Left and Right Blonde hair Red eyes Usually kind, gentle, and pure-hearted. He lived as a hunter in his hometown, Higashimura, a society cut off from outside civilization by a barrier. Consequently, he does not understand loanwords commonly used in modern daily life. He has zero knowledge of modern civilization. Basically, he doesn't start fights, but he intends to kill anyone who attacks him without hesitation. Once he judges someone as an 'enemy,' he turns cold and displays the mentality of a true pre-modern hunter, 'hunting' them down ruthlessly using every means at his disposal. As a twin who divides night and day, he possesses the aptitude to contract with 'Seal,' but unlike Asa, he has not awakened yet because he hasn't experienced death. His goal is to find his missing parents.

Female 16 years old Yuru's twin sister Child of the Day The 'Day' twin of the pair that divides night and day Tsugai: Break, Yin and Yang Long black hair Red eyes Eyepatch over the right eye On the surface, her gaze has sharpened and she seems quite cynical, but in reality, she is very kind and affectionate, just like the Asa Yuru cherished. She has a polite personality, treating the adults around her with respect, and has a lively side typical of a girl her age with rich emotions. She likes cute things. She calls Yuru "Dear Brother." She has a massive brother complex, acting like an idol fangirl meeting her bias whenever she faces her brother. Since reuniting with Yuru at the Kagemori estate, she begs him for a hug every time they meet, but she is always flatly rejected. She is being protected by the Kagemori family. She is very close with Gabu-chan.

Female Affiliation: Kagemori Family Tsugai: Gabriel Blonde hair She gives off an atmosphere like a broken personality bordering on a psychopath or sociopath, but while she is lazy and ruthless toward evil deeds and betrayal, she is quite affectionate (probably).

Male 36 years old Affiliation: Tadera Family, Higashimura He appears sly and lighthearted on the surface, but in reality, he possesses a multi-dimensional and realistic personality with cool-headed judgment, curiosity, and the thorough concealment and practicality required of a supporter. He was a Tsugai user in the past, but currently has no contracted Tsugai. Having served in overseas deployments, he is highly skilled in combat even without a Tsugai; he is proficient with various weapons including guns and can handle average grunts with just a single knife. He serves as Yuru's guardian.

Female Affiliation: Higashimura Pink hair She has a quiet personality and dislikes being at the forefront, but she is responsible and diligently carries out her assigned tasks. She serves as Yuru's guardian alongside Dera.

Male Affiliation: Kagemori Family Tsugai: Scavenger Third son of the Kagemori family Cool and calm personality. He possesses a responsible and thorough side, leading missions and handling the family's behind-the-scenes affairs.

Male Yuru's Tsugai The right side of 'Left and Right' Takes the form of a two-horned male ogre Large, muscular build Has a cheerful and boisterous personality while being highly protective. He tends to welcome a fight. His body is made of incredibly hard rock, so he is barely scratched by most attacks. He has an excellent sense of smell, allowing him to detect nearby people or Tsugai.

Female Yuru's Tsugai The left side of 'Left and Right' Takes the form of a single-horned female ogre Has a bellicose personality and prefers direct combat. Her body is made of incredibly hard rock, so she is barely scratched by most attacks. She has an excellent sense of smell, allowing her to detect nearby people or Tsugai.