Aika marries Kazuhiko, becoming stepmother to his withdrawn adult son Naoya. No matter how often she tries to talk to him, he refuses to open up. One day, Aika sees Naoya being bullied by his adult classmates and goes to his room to comfort him. When she brings up what happened, Naoya flies into a rage and rapes her. It is a forbidden secret that should never have happened, but Naoya tells his delinquent friends about what he did. Aika's hopes for a happy family collapse as his adult friends begin targeting her too...