My father recently remarried, but he's hardly ever home due to work. So it's just me and my stepmother, Shinobu, living together. One day, I happened to pass through the kitchen and accidentally caught her masturbating. That night, I couldn't stop thinking about it and ended up jerking off myself. Soon after, Shinobu came into my room, and our relationship quickly changed. Now it's normal for us to bathe together, and we've grown so close that we're comfortable spending time together even without my father around.