High school freshman Kosaka lives a gray, isolated existence. Home means physical abuse from her mother, and school offers no friends. Everything shifts when she notices Majima Issei, the popular baseball club member with a crooked smile. A small, ordinary encounter sparks a first love so intense that for the first time she feels alive. But Majima carries a hidden affliction: an octopusification curse. Over the course of six months, his body slowly transforms into that of an octopus, and episodes of violent, involuntary change threaten not only himself but those around him. Kosaka, determined to stay by his side, commits to fighting the curse alongside him. Their bond deepens as they navigate the countdown, but obstacles multiply. Majima’s mother, fearing her son might kill someone in his transformed state, intervenes by confining him to protect an imagined dignity. Kosaka refuses to accept this and makes a radical decision to rescue him. Ultimately, the story reveals a family secret hidden behind closed doors, forcing Kosaka to make one final, decisive choice. The narrative arc traces a pure, painful romance under a supernatural deadline, blending love, horror, and the question of what remains when a person’s body betrays them.