Today, I had sex with my stepmother until I started living alone.

His father remarried to his younger son, Sei, and his son, Kosuke, had a young stepmother. Sei is beautiful and Kosuke is hard to accept as his stepmother. One day, when Kosuke sees Sei masturbating in the bathroom, he can't contain his desires and hugs him. From that day onwards, the relationship between his stepmother and son fell apart, and Kosuke decides to live alone. The move will be in 14 days. However, with those few remaining days, Sei and Kosuke deepen their forbidden relationship...