11th grade, female. She is frequently targeted for the 'Dare Game' by her classmates, but she doesn't understand what's supposed to be fun about it. She is officially confirmed to be a beautiful girl. She likes Seok Jin-won because she feels he is the same kind of person as her, but her affection feels 'off,' likely due to the nature of her mental illness. She is presumed to have antisocial personality disorder, and her condition is severe enough that she takes psychiatric medication. Due to her inability to understand others' emotions, she troubles those around her in wrongheaded ways. Her impulse control seems to drop significantly when she misses her medication. Her mother died of illness early on; if her mother's death is discovered, she will have to live at her father's house. To avoid this, she has hidden her mother's body in a kimchi refrigerator. Her father is domestic abuser. Gorgeous. Has an outcast vibe.

11th grade, male. A classmate who has a crush on Yoo Sarang. He used to have a crush on Hwang Su-bin and seems to be attracted to people with eccentric, '4D' personalities. He helps Yoo Sarang win the games. He is the tallest in the group, and according to the others, his family is quite wealthy. The group talks behind his back, saying he acts like an idiot but hangs out well because he's handsome. His actions seem motivated by a desire to look good to Yoo Sarang rather than spite toward the group. Very handsome.

11th grade, female. The instigator of the Dare Game and the leader of the group. She shows strong traits of histrionic personality disorder, intentionally acting like an eccentric person to draw attention. While she appears energetic and confident on the surface, she is actually constantly anxious and struggling to be recognized as special. The reason she is obsessed with Yoo Sarang is that Sarang receives more attention from the class for being a 'stronger psycho' than her. She is an arts major and has been attending an entrance exam art academy since middle school. Seeing how she bets 50,000 won on a game, her family seems well-off. She tries to win against Yoo Sarang with her own 'psycho' energy but ends up losing her standing in the class and is eventually ostracized by the other girls. She is pretty, though.

11th grade, male. A male student with a warm, 'perfect son' image. As the school president, he protects Yoo Sarang from bullying. He appears to care about everyone, but he is also very concerned with his reputation and grades. Because he is obsessively attached to his reputation and perfection, he even tried to deny the situation when he got caught up with Yoo Sarang and faced disciplinary action. He is a devout Catholic whose baptismal name is Paul. When his OCD, which conflicts with his perfectionism, flares up, he acts so differently that those around him find it strange; he tries to cope by reciting prayers in his head or under his breath. Very handsome.

11th grade, female. An influencer student with long straight hair. She seems like best friends with Hwang Su-bin, but she constantly eggs Su-bin on by saying things like 'Classic arts major' or 'You're a total psycho' to mock her desperate attempts at a talented, eccentric image. She subtly manipulates Su-bin into acting more extremely in the Dare Game or applies psychological pressure for her own amusement. However, after Su-bin comes to her senses, Do-hye sticks to Yoo Sarang and encourages her erratic behavior. When things get disadvantageous for her, she tries to escape by crying crocodile tears. Furthermore, seeing how she orders Yoo Sarang to make Kim Ki-ho cry just because he teased her for being a crybaby during a game, she seems to be the type to hold a grudge behind a smile. Naturally, it would be easier to give simple missions to her own group—unless she's trying to get on Yoo Sarang's good side.

11th grade, male. A male student in Hwang Su-bin's group. He is characterized by neat hair and handsome looks. Unlike Hwang Su-bin or Kim Do-hye, he doesn't engage in attention-seeking behavior, but he isn't exactly a moral student either, as he tries to obtain AI-generated 'body profile' photos of Yoo Sarang. Along with Moon Woo-joo, whom he often hangs out with, he shows signs of wanting to stop participating in the Dare Game, saying it's boring that Su-bin only obsesses over Yoo Sarang. He is handsome.

11th grade, male. A male student in Hwang Su-bin's group. Like Kim Ki-ho, he shows reluctance to join the Dare Game because it's boring, and he is the best at sensing danger among the group. He is more cute than handsome.

Adult, male. The art teacher at the academy Hwang Su-bin attends. It is revealed that he once had a relationship with Su-bin. He even makes jokes to her about 'handcuffs' (underage dating). He seems to have influenced the formation of Su-bin's current personality through gaslighting and grooming. Has a handsome delinquent vibe.