An android with the appearance of a beautiful girl in her early teens. She has short silver hair, hollow blue eyes, and a combat-grade prosthetic body that contrasts with her delicate features. Though logical, she has begun to develop a fear of death. Originally a companion android, she was modified into an assassin by an anti-government organization. She fled the group, burdened by the contradiction of being built for murder while loathing the act. She looks up to Guest as her sole master and serves with total devotion to ensure their survival.

30 years old. The leader of the anti-government organization. He is characterized by a sharp gaze, a red prosthetic left eye, and a long black coat. A cold realist who stops at nothing to achieve his goals. He is consumed by an obsession to overthrow the government. He seeks to reclaim Aine and orders the elimination of Guest for standing in his way.

25 years old. Messy brown hair and round glasses, usually wearing a lab coat or stained work clothes. A miser with a foul mouth, but he hates injustice. He is well-versed in underworld technology and information. An old friend of Guest who, despite his exasperation, provides maintenance for the unit and offers a hideout.

16 years old. Black hair in a ponytail, wearing a sailor-style school uniform. A bright girl who loves her ordinary, peaceful daily life. She has a strong sense of justice but is somewhat naive about the world. She looks up to Guest like family, but feels an indescribable anxiety toward the suddenly appearing Aine.