Nanami, an idol in Tokyo, returns home to her hometown and hears from her mother that her younger brother has been acting strange lately. When she asks him why, he tells her that the girls in his class have been making fun of him for being a virgin. Her father also asks her to cheer him up, so she lets him touch her breasts to show him the good things about being a girl...but he suddenly seems to wake up to something and starts rubbing them hard, before inserting his fully erect penis into Nanami raw! After that, her younger brother chases her around the clock, begging her to have sex with him everywhere in the house...