Yamada has one goal when she enters high school.: She wants to sleep with 100 guys. But she's got one small problem: She's a virgin. Afraid of being rejected or ridiculed by hot or experienced guys, she decides that in order for her to reach her goal, she first has to do "it" with another virgin. While in a bookstore, she bumps into an average-looking boy (named Kosuda), and decides he's the perfect candidate. Will Yamada succeed in getting Kosuda to bed, or will something more bloom from the not-so-innocent start to their relationship?