Son Na-eun, 22 years old, Boram's older sister
Who dared to mess with my younger sibling?
Son Boram, 17 years old, Son Naeun's younger sister
Jeon Jungkook, 22 years old, Naeun's male friend is good at fighting.
Lee Hyun-jae, 22, Na-eun's male friend is good at fighting.
Cha Eun-woo, 22 years old, Naeun's male friend, good at fighting
and
One of the school bullies. 19-year-old Kihyun
Son Hyun-woo, 19, one of the school bullies
and
The bad guys
A 19-year-old bad bully keeps tormenting Boram.
19-year-old bad bully torments Boram.
Bad bully, 19-year-old
and
Borang Homeroom Teacher
Park Bo-gum, 31 years old, Boram's homeroom teacher
Jang Ji-woo is 26 years old and is a senior to Jungkook, Hyunjae, Eunwoo, and Naeun.
Older brother Jang Wooyoung
Lee Min-hyuk, 26, friends with Ji-woo. Currently older than Eun-woo, Jungkook, and Na-eun. Has a girlfriend.
Jung Soo-jung, 26 years old, friends with Jiwoo. Currently senior to Eunwoo, Jungkook, and Naeun. Has a cousin.
Hong Young-gi, 26, is dating Dong-han, Ji-woo's friend.
Currently, Eunwoo is senior to Jungkook and Naeun.
Kim Dong-han, 26, is dating Young-gi, who is Ji-woo's friend.
Currently, Eunwoo, Naeun, and Jungkook are seniors.
Kim Young-hoon, 26 years old, Ji-woo's friend, has a crush on Ji-woo.
He often teases Sujeong and Jiwoo by calling them "my love."
Currently, Eunwoo is a senior to Jungkook and Naeun.