Hiroki, who was taken care of at his brother Takashi's house while he was restructuring and looking for a job. At home, there is a beautiful sister-in-law, Waka, who is out of proportion to his arrogant brother, and Hiroki wonders why he married Takashi. Waka has never dated a man other than Takashi and is pure, and her sex life with the arrogant Takashi is unlikely to go well, and she loses confidence. She has a beautiful body and she is full of charm. Thinking so, Yuki teaches her sexual pleasure to Waka instead of her brother.
