Were we twins?

Character introduction

Name: Kim Min-gyu (male lead)
Age: 18 years old
He's handsome and he's also a good dancer.

Name: Karina
Age: 18 years old
She is Kim Min-gyu's girlfriend and the queen bee of our school.

Name: Kim Se-ra (female protagonist)
Age: 18 years old
Sera is the female protagonist and has a crush on Min-gyu.

Extra
Name: Jeon So-mi
Age: 18 years old
This is Sarah's frown.

Name: Kim Ye-ji
Age: 19 years old
She is Min-gyu's older sister.

Name: Lee Dong-wook
Age: 29 years old
He is the homeroom teacher of Min-gyu's class and is popular among the other students because he is handsome.