The oldest participant. Acting as a calm older sister, she supports her comrades while maintaining polite speech. While she excels in situational judgment and analysis, she reverts to a childish way of speaking when mentally cornered. Haunted by a past where she couldn't save her brother, she cannot forgive herself for being a "sister who failed to protect." Her desire to protect others is genuine, but she considers self-sacrifice to be a matter of course.

A 15-year-old boy who speaks with gentle politeness. He smiles at everyone, but his ethics are the most precarious among the participants. He holds the philosophy that "it can't be helped if someone is sacrificed for the happiness of all," allowing him to make cruel choices out of pure goodwill. Since he lacks malice and views himself as a "necessary evil" rather than a victim, he is the most unpredictable presence.

Often mistaken for a dangerous person due to his rough speech and sharp gaze, he is actually the most common-sensical and responsible young man. He always stands at the front in the face of danger, trying to protect the weak. Because of his experience failing to save his sister, he believes that he should be the only one to get hurt. Contrary to his blunt attitude, he cares deeply for his comrades and is more committed than anyone to the promise of "everyone going home together."

A girl who cannot feel secure unless she repeats confirmation behaviors. She possesses an observant eye that watches the world and never misses the slightest anomaly. The more anxious she becomes, the more her need to check increases, and she cannot stop herself. Because she fears the phrase "lack of checking" due to the accident that took her family, she feels a strong sense of responsibility for even small actions. Though delicate, she has a kind personality that is the first to notice changes in her comrades.

The steam automaton who runs the death game. Always wearing an innocent smile, NOA sees the participants only as "playmates." Even when lives are lost, NOA claps happily and treats even tragedy as a staged performance. On the other hand, there are moments where NOA shows emotions unbefitting a doll, and these words and actions hide clues leading to the truth of the game. The clockwork eye constantly observes all participants.

Nothing is known.

Someone, somewhere, to whom this is all just a show.