Yoon Seeun was the only child in her family. The moment her parents passed away in a car accident, she had no one else to turn to. That's when Shim Jayoon's grandfather - who was indebted to Seeun's late grandfather, decided to take her in.

Yoon and Seeun didn't welcome each other's beginnings but did with their endings.

when morning comes, pleasw leave it in my hands you know we'll regret it

Nagising na lang si Seeun nang wala siyang naaalala tungkol sa sarili niya. Ang una lang niyang nakita ay ang magandang doctor na may green na bangs, si Doc Jayun.

Imbis na matuwa si Raine (Y) sa manliligaw ni Diane (SE), sobrang naiinis pa siya dahil sa mga katarataduhang ginawa nito sa kaniya. There's no way that she's going to let that guy get her precious best friend! Ang tanging solution na naiisip niya: ang paalisin si Marky! A yoonseeunz au wherein Yoon looks after her bestfriend's suitor's intention!