The Daruma is a central figure in the lethal children's games that form the core of the narrative. This entity first appears as a seemingly ordinary Daruma doll, a traditional Japanese talisman associated with good luck and perseverance, but it is immediately revealed to be a malevolent and supernatural being. Its initial action is to explosively decapitate a high school teacher, emerging from the remains of the teacher's neck before landing on a desk to address the terrified students. From this moment, the Daruma establishes itself as an agent of cruel, divine will, forcing the students to participate in a deadly variant of the classic children's game Daruma-san ga koronda, which is equivalent to Red Light, Green Light. The doll is animated with a frightening expressiveness, its simple features capable of conveying an unsettling and judgmental awareness as it monitors its victims. It is not a passive figure but an active enforcer of the game's rules.

The Daruma's role in the story is strictly that of an antagonist and a game master for the initial trial. Its primary motivation appears to be the enforcement of the deadly game for its own sake or on behalf of higher powers, showing no mercy or hesitation as it executes students who fail to follow the rules. The penalty for moving while the Daruma is facing the players is gruesome; their heads fill with red marbles before bursting, a horrific spectacle that establishes the life-or-death stakes of the entire narrative. This first game serves to filter the participants, with the doll allowing the survivors to progress only once a small red button on the back of its head is pressed. The Daruma itself presents a timer, counting down the minutes the students have left to live, thereby adding a layer of psychological pressure to the physical danger. The entity is cunning and sadistic, intentionally varying the timing of its turns to catch the players off guard and increase the chaos.

Key relationships are primarily defined by the Daruma's role as the persecutor and the group of students, particularly the protagonist Shun Takahata, as the victims. The doll's focus is indiscriminate, targeting any student who moves out of turn. One key interaction is with a student named Satake, who is the first to deduce that pressing the button on the doll is required to end the game. Ultimately, it is Shun who successfully navigates the deadly field and presses the button, making him the victor of the Daruma's game, though the class representative accompanying him is killed by the doll at the last possible second. This victory allows Shun and a handful of others to move on to subsequent, even more bizarre challenges, while the Daruma's purpose is fulfilled and it is not seen again in the same capacity. The Daruma does not undergo any character development; it remains a static, implacable force of nature from its appearance to its disappearance.

In terms of notable abilities, the Daruma is a supernatural entity capable of flight, teleportation, and causing instant death through decapitation or cranial explosion. Its most prominent ability is to act as the omnipotent arbiter of its game, with the power to sense the slightest movement from any player within its field of vision and to execute them without physical contact. It has control over its own form, appearing as a simple doll but demonstrating a fleshy, uncanny texture in its live-action depiction. The Daruma also has a direct connection to the divine or alien forces orchestrating the worldwide death games, serving as their physical representative for the first trial and manifesting from the body of a slain teacher, blurring the line between the mundane and the supernatural.