In Neo Tokyo in 2XXX A.D., eleven strangers, each with a shadowy criminal past, wake up in a deserted warehouse and are confronted by the enigmatic Mr. K, the manager of the Black Papillon Foundation. They are told they’ve been gathered for a game devised by The Baron, the organization’s leader, with the stakes of 300 million yen and a fresh start by erasing their criminal records if they reach his mansion within eleven hours. Each participant wears a left-wrist bracelet that marks the countdown and carries an alarm that pings when hunters approach within 50 meters. The bracelets also house needles that deliver a lethal poison if someone tries to remove them or if time runs out, forcing everyone to keep playing or face a deadly consequence.
Once unarmed, they are divided into three teams and the game begins in earnest. The first jolt comes when Bigmac is shot and killed by hunters, signaling that this is no ordinary game and that real firearms are now part of the danger. The three teams split routes, and Fake manages to seize a gun that Snake had stolen from a hunter, gaining control of his squad. The trio formed by Jingi, Oolong and Jasmine encounters hunters after emerging from a tunnel; they fight bravely but are ultimately killed. Meanwhile, Ace, Micro and Tall manage to hotwire a car thanks to Micro’s technical skill, though Ace is killed by a hunter in the process.
The tension intensifies as Fake’s brutal choices collide with the others’ survival instincts. After some dramatic moments, Coco’s quick thinking stalls Fake’s plan, and Prince is shot and falls to his death. Micro successfully deactivates Ace’s bracelet, revealing a black butterfly tattoo on Ace’s wrist that he and Tall share. Hunters persist, and a deadly pursuit ensues, resulting in the demise of Micro and Tall during a tense car chase. Coco and Snake manage to evade further hunters for a time, but Coco is wounded. With the clock ticking, Coco confides why she hates men, yet admits that men like Snake do have a place in her life, and she entrusts him with her compact as a memento before taking a bullet meant for him fired by Fake. Snake uncovers a chilling truth: apart from himself, all participants wear a black butterfly tattoo, marking them as The Baron’s children despite their different mothers.
Fake is soon killed by a hunter and, after slipping off his bracelet, Snake reaches The Baron’s mansion as the last player standing. There he meets Mr. K again, and it’s revealed that the two plotted to let Mr. K seize control of the Black Papillon Foundation, while Snake would be handed the man with the crescent-shaped scar who killed his parents years ago. Believing this man to be The Baron, Snake confronts him only to find him dead and with no scar to speak of. The twist deepens when Mr. K shoots Snake and discloses that he himself is also one of The Baron’s children, making him the eleventh player and explaining the film’s title. In a sly turn, Mr. K had rigged the game to include real deaths to eliminate his siblings, and he turns out to be the very man with the crescent-shaped scar. The moment suggests a grim victory for Mr. K, but Snake survives his wounds and later infiltrates a bizarre costume party at Mr. K’s venue. He confronts and kills Mr. K, only to learn that Coco’s compact saved his life at the last moment by deflecting a potentially fatal shot, just before he himself is killed by Mr. K’s bodyguards.
