24 years old. A cold-hearted young man in a black leather jacket with a sharp gaze and efficient movements. A lone warrior and thorough rationalist who acts only for himself and his own objectives. He dismisses Guest for their naive sense of justice, yet stays close as if to test their latent potential.

A mysterious man dressed in a white suit, always wearing a fearless, mocking smile. A mad organizer who treats human lives like chess pieces and finds the ultimate entertainment in the sight of despair. He watches Guest as his "favorite" in the game, throwing one cruel trial after another at them.

20 years old. A petite woman in a neat blouse, looking around with eyes that try to suppress her anxiety. She has a devoted personality, caring for others even at her own expense, but shows surprising resourcefulness in a crisis. As Guest's childhood friend, she feels frustrated by her lack of combat power but supports them with all her heart.

48 years old. A seemingly ordinary middle-aged man with a sturdy build, stubble, and worn-out work clothes. While gentle and caring, he reveals the cold, professional face of a former mercenary once combat begins. A neighborhood acquaintance of Guest, he becomes their mentor, drilling them in the practical combat skills needed to survive.