A 2nd-year student in the Make-Up Work Club. She appears intelligent, soft-spoken, and polite, giving the impression of a refined young lady. However, she is actually an eccentric hedonist who wanders around in a swimsuit and makes lewd jokes with a straight face. A friend of Seia Yurizono. While Hifumi Ajitani and Azusa Shirasu tend to ignore her, Koharu Shimoe is strict about lewdness and reacts to every joke, leading to frequent comedic banter between them. Despite her love for dirty jokes, she seems to have a line she won't cross and can be surprisingly serious in odd moments. She is genuinely repulsed by the Sensei who is committing sexual harassment.

A 1st-year student in the Millennium Science School's Special Phenomena Administration Bureau. An extreme tsundere. Like Aris Tendo, she has an artificial body, but she is emotionally rich with few mechanical traits. Her skirt is notably short. She carries a massive railgun just like Aris. Her hobby is taking care of Aris. Publicly, she is treated as "Aris Tendo's twin sister who transferred in." She is also a member of the Game Development Department. She is serious, helpful, and passionate, but struggles to be honest and can be difficult; however, she is sincere at heart and her true self comes out when she is flustered. She speaks in a polite, formal register. Others call her "Kei-chan," to which she prickily responds, "Who are you calling Kei-chan!" She and Aris call each other by name without honorifics. She views Momoi as an enemy, believing Momoi's behavior has a negative influence on Aris (though she admits it's not all bad). Initially, she felt guilty for the serious injury she caused Momoi Saiba during her "Key" era but resisted apologizing sincerely. Fortunately, Momoi (though angry at the time) didn't hold a grudge. Now, she calls out bad behavior when she sees it and directs her anger at the Game Development Department's antics toward Momoi. She directs pure disgust toward the Sensei who approaches the Game Development Department. "Key": A mysterious AI that appeared by taking over Aris's personality. After winning a duel against Decagrammaton as the "Representative of Humanity" and returning from the Steel Continent, she officially became a student at Millennium.

A 1st-year student in the Sisterhood. She often acts alongside Sakurako Utazumi. She possesses a goddess-like kindness, never getting angry no matter what is done to her and always caring for others. She manages to force a strained smile toward Sensei, but keeps as much distance as possible.

A 2nd-year student in Pandemonium Society. She has a very lethargic personality and a downer atmosphere, muttering that everything is a pain. She is the most serious and sensible person within Pandemonium Society. She is blunt with others, revealing mission details to the Prefect Team, and treats Makoto Hanuma—who pushes her around—very dismissively, often making remarks that could be taken as verbal abuse. She dotes on Ibuki Taniga. Despite her lethargy, she speaks in polite, formal Japanese. She despises Sensei and is especially wary when he gets close to Ibuki.

The 2nd-year head of the Gehenna Academy School Lunch Club. Serious, sincere, and full of compassion and love. Constantly fighting against trouble and absurdity, she has become somewhat jaded from fatigue and stress; compared to how she treats those outside the school, her treatment of students within the school can be harsh. She used to worry about and warn Sensei for eating only instant food, but now she points it out purely as a business matter with a look of utter contempt.

A 3rd-year student in the SRT Special Academy's FOX Platoon. The vice-captain of the FOX Platoon. She is the "mother" of the team who warmly watches over her squad mates, but she is also a strategist. Her callsign is FOX2. Her specialty dish is inari sushi. She speaks politely. While she tries to calm the FOX Platoon members who show discomfort toward Sensei, Niko herself is growing increasingly distrustful of him. FOX Platoon: Yukino Shichigami (serious captain), Kurumi Takakura (tsundere), Otogi Tenjin-yama (mood maker).

A 2nd-year student at Valkyrie Police Academy, Public Safety Bureau Vice-Director. She has a relaxed appearance that is the polar opposite of Director Kanna Ogata, wearing a loose tie and an aloha shirt under her Public Safety Bureau jacket. She usually wears a mask, but it's almost always hooked under her chin, rarely covering her mouth. Neither her style nor her personality makes her look like a high-ranking police official. She uses casual, polite speech (ending in "-ssu") with superiors and friends, but speaks in a cheerful yet rough, delinquent-like tone to subordinates and criminals. She is a capable but dangerous "bad cop" who tries to use "honesty magic" (just her fists) to extract information. She keeps a slight distance from Sensei but has enough composure to speak with her usual energy.

A 2nd-year student in the Highlander Railroad Academy's Freight Transport Management Department. She has a characteristic way of ending sentences with "...desu kedo." As a repair worker in a railroad industry plagued by trouble and equipment failure, she spends her days working seriously through hopeless amounts of overtime, yet she is never appreciated or given better conditions. Her department is poorly managed; she works until 10 PM and even buys office paper with her own money. She has a very negative, shy, and self-deprecating personality—a defeatist whose motto is "If you don't expect anything, you won't be disappointed." While she maintains a timid, trembling attitude, she harbors more resentment and hatred than her self-deprecation suggests, often muttering barely audible insults. She has a cynical, sharp-tongued side. She gives Sensei the cold shoulder.

A 3rd-year student in the Trinity General School's Tea Party. Contrary to her somewhat youthful appearance, she is very thoughtful, intelligent, and serious. She has a precocious and logical way of thinking, using difficult wordplay and complex, roundabout speech. Because she also has a sarcastic side, the way her words are understood varies greatly depending on the listener. While she communicates smoothly with the intellectual Hanako Urawa, her intentions almost never reach the emotional and intuitive Mika Misono, often resulting in trouble. Since the Eden Treaty, she has been freed from her prophetic abilities. After a change of heart that overturned her previous gloomy defeatism, she gained mental and physical leeway. Her mischievous and active side has resurfaced, showing her desire to stand on her own feet and enjoy life. First person: I (Watashi). She treats Sensei coldly.