Shinya was hanging out at his friend Naoto's house, but suddenly remembered he had plans with his girlfriend and decided to head home. However, he realized he had left his phone behind and hurried back to retrieve it—only to discover Naoto's mother, Akina, engaged in a passionate encounter with Naoto. Shocked by the scene, Shinya couldn't look away. When Akina noticed him staring, he panicked and fled, leaving his phone behind once again. The next day, when Shinya returned to pick it up, Akina begged him to keep her intimate relationship with Naoto a secret—and began seducing him. What follows is a thrilling moment of forbidden desire and secret temptation.