Kim Ri Na is a straight A student. She's hardworking & hopes to graduate from Kang university, a university only for the top students. In her family, she is the only child, they're rich but they couldn't care less about what she does. She's actually not bad-looking but becasue she wears glasses so no one really notices it. You'd expect her to be the snobby princess type but never once has she touched her parent's given allowance. 

Young Baek Jin is a straight F- student. He's a sort of playboy but he doesn't go anywhere far with his 'affairs' with girls. He's also the leader of the school's scariest gang, "살인자" which literally mean Killers. He has an older brother (Young Baek Suk) but he totally despises him. He lives with his gang together at an appartment. 

Ri Na & Baek Jin both study in the same school, same class & they both have bad impressions of each other. Until that one incident, they had a one night stand unintentionally. Now, that's not all. What if the rich "nerdy" princess had gotten pregnant ? Will gangster "killer" boy be there for her unconditionally or will he decline his responsibility? Tune in to find out if these unlikely couple will get their happy ending!