I'm Shintaro. My friend Takehisa, who came to Tokyo from the countryside of Shizuoka for job hunting, asked me to let his younger brother Makoto stay at my place in the city for about a week. One day, I left work early and returned home, only to catch my wife Miho and Makoto in the middle of having sex. Trembling with rage, I confronted Miho and demanded the full story, pressing her for every detail. What I uncovered was a far more complicated situation than I ever imagined.