Momoko's mother is a former hostess who was married to a small-time gangster and counterfeit dealer, Momoko's father. She divorced him after their daughter's birth and remarried the male obstetrician-gynecologist who delivered Momoko. The divorce motivated her to move to Tokyo with her new husband, leaving Momoko behind to live with her father. Momoko herself encouraged this arrangement, reasoning that she wanted to remain with her father even though both of them understood she would probably have been better off in her mother's care. Her departure marks one of the reasons Momoko builds a life centered on fantasy and self-reliance rather than familial bonds. In Momoko's eyes, the mother represents the superficiality of the adult world, having prioritized her own romantic and personal desires over her child's stability. Her role in the story is largely that of an absent figure whose absence shapes Momoko's independent and isolated outlook. She appears only in a dreamlike sequence during the film's climax, where Momoko re-imagines her own birth and hears her mother remark that the unborn baby really wants to live, a line that reinforces Momoko's own will to fight for her friend. No further details about her personality, motivations beyond seeking a new marriage, or development are provided in the narrative, and she has no notable abilities or additional relationships explored.