Yongsun and Moonbyul are the queens of the school hallways. Top of the food chain. Head es in charge. But they weren't exactly the nicest people. So one day they were hanging out at their favorite diner when they decided to play a little game. "Whoever loses has to win over whoever enters the door first" It was a deal. Yongsun Won. Moonbyul lost. But when sweet, innocent, Jung Wheein entered the door first, Moonbyul didn't feel like losing at all.

Long-time couple Yongsun and Moonbyul are practically inseparable, but when Yongsun feels suffocated by their relationship and wants to spread her wings; Moonbyul loves her too much to stand in her way. But as they try to move on with their lives they are continually reminded of what they once had, and temptation to go back is never far away.