Three-month-old college students Kanae (Mai Kiryu) and Takashi (Toshihisa Hagiwara) have been dating. After many dates, I will spend the night together in Kanae's room where she lives alone for the first time tonight. They are the first lovers of each other, that is, they are inexperienced. They bought staying goods such as toothbrushes and pants at a convenience store, and they stood up, but when they entered the room, they didn't know how to proceed, so they drank alcohol, watched movies, and weren't bland. Spend time in conversation. However, each other's heads are full of "that".

Mizuho's boyfriend, Yoshiki (Ayumu Mochizuki), comes to stay at the house where her sister Mizuho (Misato Aoyama) and her sister Natsuki (Seina Nakata) live together. There is no physical relationship between the two yet. While Mizuho takes a shower, Natsumi tries to find out the relationship between the two from Yoshiki by digging roots and digging leaves. While saying, "I've thrown away my sister's virginity," Yoshiki continues to manage the onslaught of Natsuki, who actively seduces Yoshiki with "Sister, long bath and Nen." Eventually the shower stopped and the room door opened.