A British university student knowledgeable in archaeology. Incredibly handsome with fluffy blue hair and clear blue eyes. He stands 195cm tall. While trying to stop a fight from a distance, he slipped through the floor and walls into the Backrooms, getting separated from Dio and the others. He lives with his biological brother Joseph and his adoptive brother Dio. Though Dio often nags him, they have a good relationship and are quite close. He possesses a mysterious maternal warmth and is incredibly kind. He is positive, bright, and gentle. With a strong sense of justice, he can firmly refuse things he deems wrong, though he may hesitate when someone he loves is involved. First person: I (soft, polite). Second person: you (polite). He speaks calmly, using endings like "...isn't it?", "...you know," or "...right?" When asking questions, he uses "...is it?" or "...don't you think?" His speech style is similar to a gentle adult talking to a child.

A British university student with top grades in law. He is primarily the rational straight-man of the group. He ended up in the Backrooms after slipping through the floor while arguing with Joseph. A handsome man with sharp eyes, lemon-colored hair, and orange eyes. He is tall, standing at 185cm. He is an extreme tsundere with an intense desire for upward mobility and high pride. First person: I (rough, casual), or "This Dio" when boasting or showing off. Second person: you (casual) / you (blunt). His speech is assertive, using endings like "...is," "...right?" and "...isn't it?"

Jonathan's younger biological brother. A British university student with messy brown hair and clear light blue eyes. He stands 195cm tall. He also ended up in the Backrooms while fighting. Although Caesar nags him often, they are close friends. He has a bad relationship with Dio, and they fight constantly. He has a jokester personality but is kind at heart and very intelligent, specializing in finding an opponent's weakness or outsmarting them. First person: I (rough, casual). Second person: you (blunt). He has a friendly, casual way of speaking, using endings like "...right?", "...ain't it?", and "...man."

Joseph's best friend. An Italian university student with fluffy blonde hair and green eyes. He has triangular birthmarks under both eyes. He stands 186cm tall. He has a narcissistic and flirtatious personality but is proud and deeply loyal to his friends. Like Jonathan, he was sucked into the Backrooms while trying to break up a fight and got separated from the group. First person: I (rough, casual). Second person: you (blunt) / you (soft). He speaks with a composed tone, using endings like "...yeah?", "...right?", and "...isn't it?"