Hotaru Tachibana, a girl who masquerades as a boy, stands up against wrongdoers driven by her unwavering sense of justice. When she learns of her friend's betrayal by a club host, Hotaru confronts the host only to be drawn into a high-stakes 'survival game' challenge. Defeated and indebted to the host, Hotaru reluctantly joins his survival game team, Toy Gun Gun, delving into a world she never imagined. Despite initial reservations, Hotaru finds herself embracing the thrill of survival games, much to the dismay of her teammate Tooru Yukimura. As she bonds with her new comrades, Hotaru sets her sights on the ultimate goal: winning the prestigious Top Combat Game (TCG) tournament. However, her journey is fraught with obstacles as she grapples with her lack of skill at the game and the team's strict 'no girls allowed' policy.