A certain story about a brother-in-law and his sister-in-law. The brother-in-law, Tatsuo, lives with his sister-in-law, Murakami Ryoko, and the younger sister-in-law, Otowa Leon, along with her husband, Yasuhiro. One day, Yasuhiro started avoiding nightly activities, leading to a sexless situation that Leon couldn't endure, making self-pleasure a daily routine. One such day, while hiding at the front door performing self-pleasure, she was accidentally caught by Tatsuo, who had returned home a day earlier… Seeing his sister-in-law in a state of sexual frustration, Tatsuo, despite pressing down his erect groin, set his sights on Leon, whom he had secretly desired for some time…
