Yamada sets a goal upon entering high school: to make 100 sex friends. However, she faces one small problem: she is a virgin. Fearing rejection or ridicule from attractive guys, she decides that to achieve her goal, she must first lose her virginity. While browsing for a new dictionary in a bookstore, she bumps into Kosuda, a very average boy, and decides he is the perfect candidate to help her reach her goal. Will Yamada succeed in getting Kosuda into bed, or will something more bloom from their not-so-innocent start?