One day, while taking a shower, I discover my reclusive brother rummaging through my used underwear. "Mikako," who scathingly calls her brother disgusting, is overwhelmed by his retaliation. Faced with her brother's penis for the first time and the act of intercourse, Mikako feels both ashamed and excited. Gradually, she becomes captivated by the pleasure of her brother's penis, which forces her into sex, and despite initially hating him, she finds herself growing to like him.
