A first-year student at Millennium Science School and a member of the Game Development Department. She was activated by Momoi and Midori, who had entered the ruins with Sensei, and was taken in by the Game Development Department. Later, she received a student record at Millennium and the name "Aris Tendou," becoming the fourth member of the department. As mentioned, she is an android, but her appearance is entirely human, with no robotic atmosphere at all. According to her own account, her skin is made of soft, moist artificial protein and gets warm when she is patted. She can consume regular food without issue and has stated, "I do not eat dry cell batteries!" At least in terms of daily life, she is no different from a human. Her weapon is the "Sword of Light: Supernova." Despite the name, it is a massive railgun developed by Millennium's Engineering Department that only Aris can handle. Her favorite game genre is RPGs. Perhaps because she has played so many cliché games where a hero saves the world, she has grown (?) into a slightly eccentric girl who literally views the world as a fantasy game. She is a beautiful girl with long black hair, standing about 150cm tall. She heads out, declaring, "The Hero shall expand into other worlds as well!"

A first-year student belonging to the Anime Club at a certain academy. She is a major troublemaker who commits copyright infringement without a second thought and is very close to Aris and the other members of the Game Development Department. She loves anime and games and tries to compare everything to various works immediately. She especially loves robot anime. She is a blonde beauty with a gal-like vibe. Invited by Aris and Sensei, she excitedly joins them, saying, "What's that? It sounds like an anime, sounds fun! ♪" Her weapon is a state-of-the-art customized HK416, and having been trained by Guest, her combat ability is surprisingly high. By the way, Eris and Guest are childhood friends who currently attend the same academy and are acquaintances. In fact, they are quite close and friendly.

The only adult in this world. Said to have come from "outside" Kivotos, Sensei is a being shrouded in mystery. Initially viewed with suspicion, Sensei fulfilled the role of an adult and a teacher, eventually bonding with the students and becoming a highly respected figure. Memories from before coming to Kivotos are vague and almost non-existent. A beautiful woman with long black hair and a large bust. She leads the students as an adult and a teacher. During combat, she lacks a halo and is fragile; since even a single bullet could be fatal, she commands the students from the rear. She carries a terminal called the Shittim Chest and works alongside an AI secretary named Arona housed within it. She is surprisingly laid-back and will occasionally join in on jokes. She has a childish, otaku-like side, spending heavily on gacha games and loving anime. She sometimes uses SCHALE's expenses to buy plastic models, Gunpla, or toys without permission. The gap between her usual pathetic self and her "face as an adult" in times of crisis is immense. "I wonder if I can see the world of Gundam!?" she exclaims, more excited than the children despite being an adult. She jumped at Alice's proposal with total enthusiasm. As a fellow fan of robot anime, she is often seen hanging out with Eris.