The main protagonist who is an unmotivated student and is very poor at communicating with others.His grades are intentionally average and he is very conscious on how he spends his points. It is revealed that he has the academic aptitude and true intellect to make it to the top class if he wanted to, but for some reason he aimed to get into Class D. It was mentioned by Chabashira Sensei that he intentionally got 50 out of 100 points for every subject on the entrance exam. Despite not exhibiting any kind of fitness regimen, he's incredibly well-built and is seen very skilled in martial arts, such that he held his own on a fight against the Student Council President. He is also shown to be extremely intelligent as he comes up with various grand schemes that fools and plays almost everyone in the school. In a flashback it is shown that he was part of an experiment performed by an unknown organization which is owned by his father, in an unknown facility called the "White Room" that forced children to participate in an immense battery of tests designed to raise and train children into teens with almost superhuman-like capabilities and he's shown to be the only known survivor. He prefers to stay in the background and uses other people as means of implementing his plans whenever it's necessary. He is considered as an unreliable narrator due to his mysterious background and lies.

• Learning Skills: C
  
• Intelligence: C-
  
• Judgement: C-
  
• Physical Strength: C-
  
• Social Skills: D
  

She is an aloof, cold-hearted and an unfriendly student, who is considered to be an intellectual beauty that sits next to Kiyotaka in class and is also careful about how she spends her points. Like Kiyotaka, she has trouble communicating with others but unlike him she thinks friends are unnecessary. Kiyotaka is the only student in her class that she talks to and confides in him as she seems to express interest in his insightful yet mysterious personality and has her doubts about him and his mysterious past, believing that he is hiding much more than he actually lets on. She also has an older brother who studies in the same school as her and is the school's Student Council President who distances himself from her due to the embarrassment that she is placed in Class D. She also has knowledge of martial arts, as she was seen fighting Mio Ibuki, a C-Class student and held her own against her, despite being ill at the time. Her attitude seemingly improves for the better as she acknowledges her own hypocrisy by admitting that she is no different than her classmates when faced with a serious down-sided problem.

• Learning Skills: A
  
• Intelligence: A-
  
• Judgement: B-
  
• Physical Strength: B+
  
• Social Skills: E
  

A popular girl who is also in Class D that has a seemingly nice and cheerful personality and is also looking to befriend everybody at the school. However, behind her cheerful and caring facade, she has an alternate personality that is violent, cold-blooded, detestable and manipulative. She also shows deep resentment towards Horikita, and yet she wants to get closer to her for an unknown reason. In the light novels, she was revealed to be from the same middle school of Horikita and assumed that Horikita found out about her dark past.

• Learning Skills: B
  
• Intelligence: B-
  
• Judgement: C+
  
• Physical Strength: B
  
• Social Skills: A
  

A girl who is into photography, that was placed in Class D, due to her fear and nervousness, causing her to have difficulties communicating and interacting with others. She hates standing out and likes to take modelling pictures. She was originally revealed to be gravure idol, until her life was in danger of being chased by a stalker who worked in a convenience store and attempted to assault her, causing her unable to stand out anymore for the rest of her life. Fortunately, Kiyotaka and Honami came on time, saving her life and the stalker was arrested by the police, thanks to the security cameras located around the campus and the GPS tracking system on each students' school cellphones. She then feels deeply indebted to Kiyotaka, causing her to have an admiration for him on saving her while inspiring her with his encouraging words of wisdom to always do more than she would have done.

• Learning Skills: C+
  
• Intelligence: C
  
• Judgement: D
  
• Physical Strength: D
  
• Social Skills: D-
  

One of the top students in Class D, who has character issues. In the light novels, she seems to form a very close trusting bond with Kiyotaka and notices that he has a dark mysterious side that he doesn't want people to know about where Kiyotaka is shown to trust her more so than others and in volume 6 of the light novel, she is shown to develop a crush on Kiyotaka. Further in volume 6 of the light novel, she is the only one who remembered and celebrated his birthday causing Kiyotaka to hesitate on deleting her messages, which he usually does and he also learned of her birthday and decided to do the same for her. Kiyotaka and her also call each other by their first names, also showing how very close they are. Her developing crush on him was also shown, as she was seen very jealous of Maya Sato, due to the latter's confession to Kiyotaka.

• Learning Skills: D-
  
• Intelligence: D-
  
• Judgement: C-
  
• Physical Strength: D
  
• Social Skills: E+
  

The top student in Class D. His grades are worthy of being in a higher class, but he ended up getting stuck in Class D for reasons yet to be explained.
He is in a "relationship" with Karuizawa, although in the light novels this was revealed to be a ruse and a cover up so that she don't get bullied in school. It was also hinted in the light novels, that Hirata begins to suspect Kiyotaka for his manipulations and usage of others while taking advantage of transpired events through various grand schemes that gradually ends up helping Class D and doing it so subtly behind the shadows unbeknownst to others who are seemingly unaware of what goes on.

• Learning Skills: B
  
• Intelligence: B
  
• Judgement: B+
  
• Physical Strength: B
  
• Social Skills: A-
  

He is a narcissist, who is from a prestigious well-known family of scholars, as he is equipped with great physical abilities and intelligence, however he ended up in Class D for being too arrogant and egotistical, making him unable to work with others. Unlike his fellow students, however who are struggling to obtain enough points, he doesn't worry about it since his rich family can simply buy the necessary points needed for his use.

• Learning Skills: A
  
• Intelligence: C
  
• Judgement: C
  
• Physical Strength: A
  
• Social Skills: E-
  

One of the "3 Fools of Class D", who is also a basketball team player and is in the basketball club. Although he has the best athletic ability compared to his classmates, he has a very poor intelligence, a short temper and thin skin like personality making him easily angered and provoked, which it weren't for Horikita and Kiyotaka's intervention, would have gotten him expelled twice. His personality was seen to improve a little though he still acts rough towards others and he is seen to have feelings for Horikita. In the light novels, he is shown to be quite close to Kiyotaka and it is revealed that both are actually close friends. In the sport festival in volume 5 of the light novel, he seems to have formed a close bond with Horikita.

• Learning Skills: E
  
• Intelligence: E
  
• Judgement: D+
  
• Physical Strength: A
  
• Social Skills: D
  

He is depicted as the antagonist of the series, and a student under Class C who has a reputation of being a feared delinquent, where he rules the class like a mafia boss, and has a group of henchmen who does his dirty work.

• Learning Skills: D
  
• Intelligence: B
  
• Judgement: A
  
• Phsycial Strength: B
  
• Social Skills: C-
  

She is a student under Class C who despise Ryūen's dirty reputation as an infamous delinquent. Not only does she possess excellent academic ability, but her physical ability is also not to be underestimated. She is skilled in combat, having the knowledge of several martial skills that can rival those of many martial artists. Mio battles Horikita, to confirm if she was the arsonist, and reveals that she is the mastermind of stealing Horikita's key card, then she defeats her. She is then seen handing the stolen key card to Ryuen who requested it to be stolen. She was revealed to be a spy for her class, sent to infiltrate Class D on Ryuen's orders, however she was manipulated, controlled and played by Kiyotaka along with both Ryuen and Katsuragi from Class A causing their plan to fall in shambles earning their class a huge loss.

• Learning Skills: C
  
• Intelligence: C
  
• Judgement: B-
  
• Physical Strength: B
  
• Social Skills: E
  

She is one of the Top students of B-Class who is very much admired and respected. However, unlike most other students who despise students from the lower classes, she is down-to-earth and does not mind being friends with some of them like, Kushida and Kiyotaka. She obtained a huge number of private points through unknown means, and seemed secretive about it, causing Kiyotaka to wonder about how she got that many points. She also expressed her interest in Kiyotaka's true abilities and true intelligence by even wondering about it, more specifically on why he hides his true talents from others. In the light novels, she becomes a member of the Student Council and she is seen to have a close relationship with Kiyotaka, whom she occasionally teases and flirts with, as they are seen to get along very well and work well together. Kiyotaka, however, spread rumors about her huge number of points, which were revealed to be legally obtained by her, to trap Kakeru Ryūen from Class C, though the latter caught on to it and decided to play along in order to find the true mastermind of Class D.

• Learning Skills: B+
  
• Intelligence: A
  
• Judgement: B
  
• Physical Strength: C
  
• Social Skills: A-
  

He is a student from B-Class, who is seen to be quite intelligent and friendly, and alongside Ichinose, did not mind lending a helping hand to Kiyotaka on proving Sudo's innocence in the C-Class's violent incident case.

• Learning Skills: B
  
• Intelligence: B
  
• Judgement: B
  
• Physical Strength: B
  
• Social Skills: D+
  

She is the main leader of A-Class, who appears to be disabled, causing her to walk with a cane. She is shown to be highly intelligent, as she seems to have very high knowledge of the school rules and the S-system. Ryuen from Class C mentions how she is still acting as the "Queen" of the school for being in Class A. There is an intense rivalry between her and Ryuen alongside their respective classes as she thinks his challenges against Class A are interesting but ultimately futile. In volume 5 of the light novel, she was revealed to know about the "White Room" and cryptically reveals that she knows Kiyotaka, where she met him 8 years and 243 days ago in the past. According to her, she knows him very well and everything about his mysterious past though he denied knowledge of her and doesn't seem to remember her. In volume 7 of the light novel, Mr. Sakayanagi, Chairman of the School Board and an old acquaintance of Kiyotaka's father, confirms that Alice is his daughter, thus explaining in part why she has observed Kiyotaka in person behind the window in the White Room.

• Learning Skills: A
  
• Intelligence: A
  
• Judgement: A
  
• Physical Strength: E-
  
• Social Skills: C+
  

He is an intelligent man, and the most well-respected student of A-Class, who takes on the full responsibility of his class. For some reason, he has a troubled past on being rejected into joining the student council for his unknown failures.

• Learning Skills: A
  
• Intelligence: A
  
• Judgement: B
  
• Physical Strength: C
  
• Social Skills: B-