Lee Namsoo

Tomboy, really a girl. 16 years old. Kai's ex-girlfriend. Smart and clever. About-to-be kingka  (no one knows that she's a girl except her friends) in SM High. Hates Kai's guts and wants revenge.

Park Jae Hyun

Namsoo's rich best friend who's also a tomboy. 17 years old and intelligent in her own way. Helped you transform and wants to help you get revenge on Kai. 

Song Chan Ho

Namsoo's close friend and 16 years old. Funny and could be a troublemaker. Is also a tomboy and Jaehyun's cousin.

Lee Geum Hee

Another of Namsoo's close friends. 17 years old. Sweet and loves her friends. Pretends to be Namsoo's girlfriend whenever a girl is close to Namsoo.

Kim Jongin aka Kai

Kingka of SM High. Cheated on you & regretted it (later). 18 years old and rich. Doesn't know Namsoo transformed and thinks she is a guy.