Yamada, first name withheld, is a 15-year-old girl who has just entered Takizawa High School. Easily considered exceptionally beautiful, she has only one problem with her own body, she thinks her vagina looks weird and is very self-conscious about it.

Upon entering high school, her dream was to have casual sex with 100 men but therein lies the problem, she believes an experienced partner will tease her about the way her vagina looks or simply the fact that she's a virgin. She stumbles upon the solution in the form of Kosuda Takashi, a fellow virgin, whom she believes will help ease the transition to more experienced partners.

There's only one small problem, Yamada doesn't know anything about sex or the ancient art of seduction, meaning her quest to conquer Kosuda will be a difficult one.