One day, Daisuke witnessed his best friend's mother, Waka, flirting with a stranger. He immediately realized that she was cheating, so he followed her and peeked through the window of her room. When they started doing obscene things, he filmed the whole thing on his cell phone. He then went to Waka's house, who knew nothing about it, and threatened her, showing her the pictures. With her weakness exposed, Waka had no choice but to follow Daisuke's threats...