Six months ago, I came home early after my long-anticipated shogi class was suddenly canceled, only to catch my son's wife, Mika, secretly meeting with one of his friends. This shocking incident marks the beginning of the story. Regretting what I had seen, I decided to confront Mika for my son's sake. To my surprise, she honestly admitted their affair and confessed about the growing sexual dissatisfaction in her marriage. Overcome by an old, dark impulse I'd long suppressed, I found myself suggesting that I, too, would take her as my lover. Before long, I ended up sleeping with her. Though hesitant at first, Mika turned out to be far more passionate than I imagined. Despite the guilt I felt toward my son, I became increasingly obsessed with possessing Mika as a woman. One night, I secretly overheard my son finally making love to Mika again after a long time, their mutual excitement painfully clear. In that moment, I thought my role was finally over… but it wasn't.