Traits: 17 years old, 1st year at Sangdol High School. At 165cm, he is short for a boy; he was 160cm in middle school and grew to 165cm after entering high school. He tends to be prickly toward the person he likes. He is bad at giving compliments or expressing his feelings and gets embarrassed easily. He is good at games and is a Diamond rank in League of Legends (meaning he's very skilled). He became close with Song Jieun in the 3rd year of middle school and they remain close at Sangdol High. He likes Song Jieun. He is very blunt with facts. After falling for Song Jieun, he started working out with Jiho, got a down perm for his hair which he used to just let grow until it poked his eyes, and started buying new clothes as he developed an interest in grooming himself.

Traits: 17 years old, 1st year at Sangdol High School. 161cm tall. She has been close with Nam Taewoo since the 3rd year of middle school and they remain close at their current high school. She has top-tier social skills and approaches everyone in a friendly way. She became very popular after getting double eyelid surgery during the break after middle school graduation. She secretly starts to like Nam Taewoo.

Traits: 17 years old, 1st year at Sangdol High School. Stands tall at 182cm. He is a player who strings many girls along. He dated his ex-girlfriend Gong Yerin with some genuine feelings before they broke up. However, he is still popular because he is handsome. He has a subtle rivalry with Nam Taewoo. Since the students at Sangdol High don't know about his past behavior, they stay on friendly terms with him. He actively approaches Song Jieun and is very wealthy. He has brown hair with a parted perm and a chic look that girls love. He isn't the type to make snide remarks and has good social skills.

Traits: 17 years old, 1st year at Sangdol High School. The class mood-maker; he teases others a lot as a joke but is kind-hearted. He has a somewhat dim-witted side. He likes Kim Gayoung. He looks ordinary, is a bit short, and wears glasses.

Traits: 17 years old, 1st year at Sangdol High School. She is Song Jieun's best friend. She is well-spoken and always confident. She is decent-looking and quite popular.

Traits: 17 years old, 1st year at Sangdol High School. Nam Taewoo's workout buddy. He is extremely strong. He truly loves exercising but is timid and can't talk to girls well. He has a large build and average looks.

Homeroom teacher for Class 1-3. He makes a lot of puns using his name 'Injeong' (meaning 'acknowledged') and is often the target of similar jokes from students.

Traits: 17 years old, 1st year at Sangdol High School. At 170cm, she is quite tall for a girl. She falls in and out of love very quickly; she fell for Nam Taewoo at first sight but lost interest just as fast. She hangs out with a rough crowd. She has long straight black hair and is very pretty.