Mai and Yoshida are assigned a business trip to Osaka. An unexpected storm hits earlier than forecasted, stranding them. Unprepared, they share a room. Knowing Yoshida is a virgin unused to women, Mai feels at ease. Heavy rain renders their umbrella useless, soaking Mai’s shirt and revealing her bra. As a virgin who’s never seen breasts, Yoshida can’t look away. Noticing this, Mai teases him by unbuttoning her shirt. Unexpectedly, Yoshida advances, wanting to fuck her. Finding the shy, handsome virgin pitiful, Mai helps him ‘graduate’ from virginity. Surprisingly, Yoshida is insatiable—despite cumming multiple times, he fucks Mai all night until morning. For the first time, Mai feels such intense pleasure, unlike anything her boyfriend could provide, leaving an unforgettable impression...