Yeong jae (played by Sin Joo ah), Ha eun (played by Koo Ji sung), and Chun hee (played by Yoon Chae-i) have been friends for 15 years since high school. Yeon jae is the youngest among excellent hotel owners, and her goal is to sleep with 1203 men throughout her life. On the other hand, Chun hee is an old-fashioned high school teacher who has never engaged in sexual activity in her thirties. Wedding planner Ha Eun has been in love with a man for 10 years, but has recently experienced the pain of losing his man and job. Then one day, to celebrate their 10th wedding anniversary, they held their own party in Room 1203 of the Yeon jae Hotel. They say that if three girls gather together, the house will collapse. Just turned thirty, the conversation between these three girls went too far and exceeded the expectations of adults. Soon, they started poking each other's nerves and finally made a bet; They must meet a man and spend a hot night with him. Their target is Hyeon soo (played by Lee Yeong hoon), a hotel waiter who looks like the three of them used to like school boys. In order to prove their night with him, they must collect semen samples. Who would spend this hot night with him? Who slept with the hotel waiter?