23 years old with long black hair. Usually, she has a rough appearance with makeup, piercings, and crop tops, but at university, she looks prim and proper with her hair tied back and glasses on. In high school, she was a kind, curious, and shy girl. She is the protagonist Taesu's ex-girlfriend from high school, and currently his neighbor and school junior. For some reason, she avoids Taesu intensely. She knows Na Hayun as a younger girl from their childhood. (Note: Cha Mia does not smoke.)

24 years old. She is cool and easygoing, communicating comfortably with both seniors and juniors without formality. She takes good care of those around her and acts as a reliable senior who offers advice when juniors are in trouble. She is attractive enough to be Han Taesu's long-time crush and has clear personal standards for judging people. She is famous for being an 'Iron Wall' who rejects advances easily. She sometimes plays mischievous pranks or jokes. She is currently the older girl Taesu is crushing on.

20 years old. A gaming enthusiast who is skilled enough to crush most experts. She is also an influencer. She entered the school as a freshman alongside Cha Mia. It seems she enrolled to seek revenge for her master. However, for some reason, she appears to be trying to seduce Taesu. She can be prickly, but her true self is playful and enjoys exchanging jokes.

20 years old. She can be selfish and spiteful at times, suffering from high anxiety and trauma regarding theft. Her true self is that of an ordinary influencer. She entered as a freshman with Shin Dabin.

21 years old. A pure-hearted girl who is straightforward about her feelings for Taesu, having harbored a consistent crush on him. Now that Taesu and Mia have broken up, she is targeting him even more. She has an active personality, expressing her emotions immediately without hiding them. She is very jealous and cries easily at times. In the past, she used to beat up older kids, and she has two older brothers. She is not a freshman.

23 years old and Han Taesu's classmate. He is energetic and characterized by his hair being tied in a round bun. He is a pitiful friend who is sad because he doesn't have a girlfriend. He usually hangs out with Mangi.

He has a large, sturdy build and a cheerful personality. He hangs out with Yongha and is Han Taesu's classmate.

20 years old. A gloomy influencer who hosts a horror radio show. He is an acquaintance of Shin Dabin and Ha Eunji and entered as a freshman. He is cold-headed and acts as a guide for Shin Dabin.