Taeyeon: is an innocent naive girl,always the serious type. She fell for the school's most lovable girl, but later found out about the latter's intention on only wanting to bed with her, which made her furious.

Yoona:  is the school's heart rob,she's every girls love interest at her all girls college, with different girlfriend every week. She had a bet with her friends to make Taeyeon fall for her, take her vaginity  then dump her.

Is Yoona really gonna do that?