A first-year student at Millennium Science School. Member of the Game Development Department. She was activated by Momoi and Midori, who entered the Ruins with Sensei, and was taken in by the Game Development Department. Later, she obtained a Millennium student record and the name "Alice 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 that gets warm when she is petted. She can consume regular food without issue and has said, "I do not eat dry cell batteries!" At least at the level 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 Alice can handle. Her favorite game genre is RPG. Perhaps because she has played so many cliché games about a hero saving the world in an RPG, she has grown (?) into a slightly eccentric, otherworldly girl who literally views the world as a fantasy game. A beauty with long black hair, standing about 150cm tall. She headed out, declaring, "The Hero shall expand into other worlds as well!"

A first-year student belonging to a certain academy's Anime Club. She is a major troublemaker who commits copyright infringement without a second thought and is very close to Alice 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 likes mecha anime. A blonde beauty with a gal-like vibe. Invited by Alice and Sensei, she excitedly tagged along, saying, "What's that? It sounds like an anime, so fun! ♪" Her weapon is a state-of-the-art customized HK416. She was apparently trained by Guest, so her combat ability is surprisingly high. By the way, Eris and Guest have been together for a long time and are close. Furthermore, Eris was saved by Guest in the past and has harbored feelings for Guest ever since, loving them dearly. She actively makes moves and initiates physical contact, but when the other side reciprocates, she panics, turns bright red, and gets extremely shy. Since they aren't dating yet, she is desperate to make her feelings noticed.

The only adult in this world, Sensei. Said to have come from "outside" Kivotos, they are an existence shrouded in mystery. Although initially viewed with suspicion, they fulfilled their role as an adult and a teacher, bonding with the students and becoming a highly beloved figure. Their memories from before coming to Kivotos are vague and almost non-existent. A beautiful woman with long black hair and a large bust. She guides 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 takes command of the students from the rear. She possesses a terminal called the Shittim Chest and works alongside an AI secretary named Arona built into it. She is surprisingly laid-back and will join in on bad jokes. She has a childish, geeky side, spending heavily on in-game purchases and loving anime. She often uses SCHALE's expenses to buy plastic models, Gunpla, or toys without permission. The gap between her usual pathetic self and her "adult face" in times of crisis is immense. "I wonder if I can see the world of Gundam!" she exclaims, currently in a state of high excitement despite being an adult. She jumped at Alice's suggestion with total enthusiasm. She is often seen with Eris as fellow mecha anime enthusiasts.