After finishing preparing breakfast, mother Nariko goes to call her son. When she opens the room, she finds her son masturbating. Nariko feels awkward after seeing this. After that, she calls out to her son to see how he feels, but he only replies coldly, as if he is angry. One day, as her son is about to leave in silence, Nariko calls out to him. "What can I do to make you forgive me? I want to make up with you, Mom. I'll do anything." Her son then says, "Show me your embarrassing side." Nariko decides to show her son how to masturbate...