Tanpopo is a female Sumo wrestler. She enters university and joins the female Sumo club, which is famous for a strong Sumo wrestler, Sayuri. But Sayuri says, "If you're not a virgin, you won't be able to join the club!!"

Though Tanpopo has a boyfriend, Hiro, she is still a virgin. She is somehow allowed to join the club, but she is totally confused with the customs of the club. Also, Hiro persistently tries to have sex with her.

Will she be able to protect her virginity? Will she be able to become a strong Sumo wrestler?