Serene Ramos is a self-confessed, “straight-laced” Filipina teenager who loves rules and order, but puts on a bad-girl act at school to satisfy her more extroverted identical twin, Trinity. The two of them start playing a dating game where Serene tests Trinity's prospective boyfriends by posing as her sister, causing her troubles and heartaches that turn her into the kind of person that she once hated.
In order to prove that nothing has changed, she suddenly declares to her old friends and classmates at their ten-year high school reunion that she would have sex with the next guy who steps inside the gate where the reunion is held, but luck isn't on her side when the next man is none other than Zane Dario, a troublesome bad boy and her high school nemesis.
