"I don't think just once will be enough." "Hey, mmm..." National swimmer, Moon Tae-gyeom. He has a secret behind his spectacular comeback after a long slump. The reason he finally broke his stagnant record is none other than his friend of 20 years, Yoo Seo-hae. Every time he sleeps with Seo-hae, his performance improves like magic. At first, it was just for the records. But soon, he starts to get annoyed by every single guy around her. "Yoo Seo-hae's body belongs to me, but there are too many bastards trying to covet it." ...Are we really just friends?