Nori, the younger brother, is staying at his older brother's house for a few days. He has feelings for his beautiful sister-in-law , Arisa. Arisa also had lustful thoughts about Nori's huge penis, which she had accidentally witnessed before... When Nori accidentally witnesses Arisa masturbating on a boring afternoon, he can't help but attack her! Arisa is confused, but accepts it. And her older brother witnesses the scene... He devises a wicked plan, fearing that his wife will be seduced if things continue like this.