After making a one-night mistake with a classmate at a class reunion, Mio is filled with guilt towards her husband and anxiety about her pregnancy. Her brother-in-law, Takashi, who happened to come to Tokyo and came to stay, noticed that her appearance was strange and began to explore. "According to what I heard from my brother, my sister-in-law seems to be worried about getting pregnant, even though there shouldn't be much married life at night. Maybe it's cheating..." Takashi, who has been eyeing Mio since they first met. However, he approached Mio about it...
