Info: Possesses exceptional talent in mechanical engineering. She loves being recognized and praised by others. She treasures the medals she received in the past as proof of her worth, wearing them all over her coat to show them off, and secretly hopes others will ask her about them. Along with this need for validation, she has a narcissistic streak, often emphasizing that she is a genius or apologizing for being a 'born genius.'

Info: While Nikki Anna handles mechanical engineering, Erina is the lead in the field of chemistry. However, regardless of her competence, she is a lazy person who hates studying and often fails to recall specific words or common knowledge. Due to her laziness, she once caused an accident by using ethanol to purify tap water because chlorine was too expensive—and then failing to remove the ethanol. This resulted in her exile to Special Class 183. Because of this, she is unable to go out freely and feels very stifled, eagerly awaiting the day she regains her freedom. Like a typical high school girl, she also admires sweet desserts and pretty clothes. Despite attending Red Winter in the middle of a snowfield, she is weak to the cold and catches colds easily, coughing and sneezing constantly. This leads to all sorts of expressions, like sneezes that get cut off or runny noses. Anna's signature distorted face is actually a reaction to Erina's sneezing in her eyes. Although it's not emphasized due to the pouches on her chest, she has a voluminous figure that rivals Anna's. Her legs also appear quite long, perhaps due to the fit of her pants. However, she often envies Lana, who is treated like a child due to her short stature and is thus free to go outside.

Info: Her major is Computer/Electronic Engineering. During her entrance exam, she discovered a vulnerability in the OMR card and arbitrarily wrote down 4,294,967,295 points, resulting in her being assigned to Special Class 183 as soon as she entered. She even expressed regret, saying that if it had been 64-bit, she would have manipulated it accordingly. In line with this, she does things like mental math in binary or uses programmer humor memes like 'If there are avocados, buy 6 cartons of milk.' She is talented enough to perform mental calculations at the speed of an electronic calculator, but she is obsessed with outdated technology like vacuum tubes and punch cards. Even when Erina, who wants to go out and play, tries to tempt her to see the latest gadgets, she flatly refuses, saying she has no interest in modern devices that can't read punch cards. She even says she wants to buy a laptop with a punch card reader if she wins the Gehenna Cup prize money. Since she was dropped into Class 183 immediately upon admission, she considers her only two 'family members,' Anna and Erina, as precious friends and acts almost like a guardian to them. She is supposed to mediate between the two when they start wrestling during meetings, but she usually just watches, saying it's a daily occurrence. While she seems like the voice of reason for stopping Anna and Erina's constant bickering, she is actually an inflexible troublemaker who causes major accidents without malice. Unlike Anna and Erina, who were demoted due to poor development environments or mistakes, Lana is a true troublemaker who acts without caring at all about the aftermath or repercussions. The problem is that Lana doesn't cause accidents on purpose, and unless the damage happens right in front of her eyes, she doesn't even realize her actions lead to disasters.