Laking gulat ni Seulgi nang ibalita sa kanya ng kanyang tatay na magpapakasal na siya sa kanyang kababata na merong dalawang anak. Pero mas laking gulat niya nang malaman niya na ang dalawang anak na yun ay is Irene, ang kanyang professor at first love, at si Jisoo, ang babaeng naka-one night stand niya.

Irene and Seulgi has a happy beginning but will they still have a happy ending? As the chaos came into their relationship. Would they still be stuck in each other's side?

Soulmates are something everyone dream about and finding yours is something that not many people have the luck of experiencing, but what would happen when instead of 1 you find 2 of them? Seulgi will never know why the biggest force in this universe put her (of all people) in this situation. Who's the right one? That's the problem, both of them are.