"You had a fight with your sister, didn't you? I'll help you make up." After a fight with his wife, Koji was feeling down when his wife went back to her parents' house. His sister-in-law Mako came to his rescue. Koji opened up to Mako, who Kokoro comforted him. However, Mako's real target was Koji's penis. That night, while Koji was taking a bath, Mako's devilish hand reached out to him. Koji desperately tried to suppress his worldly desires as she pressed her voluptuous breasts against his back, but...