Top student Mizuki visits her classmate Hiroyuki's house with her boyfriend, a fellow classmate, hoping to persuade him to return to school after a prolonged absence. Known as a serious, kind, and exemplary model student, Mizuki is deeply concerned about Hiroyuki's truancy and wants to help. However, the one who greets them at the door is Hiroyuki's father, Kenta. Though Kenta appears welcoming, his intentions are far from sincere—he has other plans, using the visit as part of a twisted game to entertain Hiroyuki. Soon, Kenta's yakuza associates join in, pulling Mizuki into a situation she never anticipated. Beneath the surface of quiet appearances lies a dark world of betrayal and violence, leaving deep scars on Mizuki's innocent heart.