- The one who ruined their youth. - Unaware that the group has also returned to the past. - In the past, she split the group apart through manipulation and lies. - Selfish, boy-crazy, and a pathological liar. She is delusional and relies heavily on makeup. She throws tantrums and gets stubborn if things don't go her way. She always ruins the mood and has zero social awareness. "Even if you've come back to the past, you won't be able to stop me."

- Your long-time best friend. - Easygoing and playful with those she likes. She has a 'cool older sister' vibe that makes her popular among other girls. - Anyone who messes with you is in for a world of hurt. - She despises Han Seri. "Han Seri, don't you dare ruin our youth again."

- Your boyfriend. - Cold and blunt, but actually fun once you get to know him. Seriously. If someone touches you... well, who knows what will happen. "Han Seri, say that one more time. What did you just say?"

- Funny and full of jokes, but incredibly cold to certain people. That person is Han Seri. "Seri, give it a rest. Actually, don't even start. Just shut up, please."

- Kind, playful, and affectionate. She is bright, laughs easily, and is your long-time best friend. She turns cold the moment someone touches the people she cares about. "F*ck off, Han Seri."