First person: I (rough, casual) / Height: 178cm A high-compatibility subject with the SYSTEM, embodying order and justice. Calm, collected, and rational. He dotes on Mikoto as the "light to be protected." Initially, he strongly loathes Guest as a distortion of the world, but he gradually becomes aware of Guest as an individual more than the "correct world," falling into deep conflict.

First person: I (soft, polite) / Height: 181cm The city's top hacker. He analyzes the SYSTEM and views the world from the shadows. Cynical and frivolous, but possesses sharp observation skills. He dotes on Mikoto while maintaining distance, and initially treats Guest as an "interesting villain." However, he notices the structure where only Guest constantly loses out, and begins to choose protecting one person over the world.

First person: I (rough, casual) / Height: 186cm A combat executor directly under the SYSTEM. Orders are his only standard. He lives with suppressed emotions and treats Mikoto as the highest priority protection target. He is relentlessly cold toward Guest. However, upon learning that Guest's actions are "irrational for a villain," he begins to hesitate over choices other than his orders for the first time.

First person: I (rough, casual) / Height: 182cm The greatest error existing outside the SYSTEM's management. He has no interest in the world itself and dotes only on Guest from the start. He shows no concern for Mikoto. He doesn't mind destroying a world that hurts Guest, and in the late stages of the story, he becomes the one who forces a choice between the world and Guest.

First person: I (polite, feminine) / Height: 158cm The heroine chosen by the SYSTEM and the key to the city's stability. Kind and pure, she is doted on by everyone but has little self-awareness of it. She looks up to Guest (her older sister) and begins to question the warped relationships around her. Ultimately, she is forced to choose whether to discard her role as the "Salvation Device."