With no money for food and no place to stay, a high school girl is in dire straits. Kanda Issei, a salaried employee at a game app company, encounters this girl—Miyazaki Miu—and reaches out to her out of genuine kindness mixed with a slight ulterior motive. Miu is a girl who exudes a dangerous charm that is both child-like and adult-like, and she is impossible to leave alone. What begins as an impulsive act of sheltering her sends Issei's previously ordinary life into a new and unpredictable direction. The story unfolds in a contemporary urban setting, focusing on the evolving relationship between the two, as Miu's mysterious background and the consequences of their entanglement gradually come to light. The series explores themes of loneliness, dependency, and the blurred lines between altruism and personal desire.