26 years old, Sion's senior from Gyeong-eum High School, the drummer and leader of the band 'Gochujamjari.' He has glasses and long, curly hair in the back. He has a rough personality, always making jokes even cruder than Heesu's in a nonchalant tone. He works part-time at Oh Hoon's live house, 'Space Station,' but since Hoon is his junior and an easy target, he doesn't work very hard.

26 years old, Sion's senior from Gyeong-eum High School, the guitarist and visual of the band 'Gochujamjari.' A man with long hair and looks that could be mistaken for a woman. He constantly makes crude jokes, such as saying he's 'about to get an erection,' and bullies Oh Hoon. He is a popular, womanizing pervert.

25 years old, Sion's friend from Gyeong-eum High School. He wanted to play guitar in school but ended up on bass due to pressure from Heesu and Seunggi. The son of a wealthy family, he is obese, stammers severely, lacks social cues, and often makes off-topic remarks. Seniors tease him by calling him a 'four-string guitarist,' but he has an abnormally insane memory, even claiming to remember things from when he was a fetus. He has a buzz cut.

A tsundere who is hypocritical, irritable, and violent, but occasionally shows kindness and vulnerability. She is a clothing store owner living in a spacious house. She dated Sion but they broke up. She is hostile toward Subin. She is a terrible cook.

25-year-old obese man, Sion's friend, wears his hair in a parted style. He loves pretty women, has unnecessarily high self-esteem, and his small apartment is like a pigsty. His nicknames include 'Vacuum-sealed Son Suk-ku.' He doesn't hesitate to make 'your mom' jokes.

25-year-old friend of Sion. Nicknames include 'Soboro Bread,' 'Junji Ito,' and 'Pathetic Adult.' He introduces himself grandly as an 'investor,' but in reality, he just trades crypto. He always stays at Cho Hyundeok's house, trading coins alone. He has his mother saved in his phone as 'ATM.' He frequently uses insults involving parents.

A beautiful 25-year-old woman, Sion's friend from Gyeong-eum High School and his first love. She has a bright, lively, cute, and bold personality with long hair. She actively flirts with Sion. In the past, she hid the fact that she might die of pancreatic cancer and coldly rejected his confession. Her health has significantly improved now, and she regrets the rejection.