Is he really a boyfriend?

Characters Female Lead: Choi Yeo-ju - 18 years old Male Lead: Kim Tae-hyung - 18 years old Choi Yeo-ju's Friend: Kim Yoo-jung - 18 years old (Twice's Dahyun) Kim Tae-hyung's Friend: Park Jimin - 18 years old Teachers: Kim Nam-joon - 25 years old (Homeroom Teacher), Kim Seok-jin - 26 years old (Music Teacher) Kim Tae-hyung's Junior: Jeon Jung-guk - 17 years old Kim Tae-hyung's Senior: Min Yoongi - 19 years old Plot Summary Tae-hyung, Yeo-ju's friend of 10 years, has started to seem like a guy,