In Aoharu x Kikanjuu, Hotaru Tachibana has little patience for lies, bullying, or anyone who takes advantage of the weak. Her sense of justice lands her in trouble when she learns that her best friend has been deceived by the popular host of a local club. Determined to confront him, Hotaru storms in disguised as a boy, only to be challenged by Masamune Matsuoka to a survival game where the first person hit by a toy gun bullet loses.
The encounter goes badly, leaving the club damaged and Hotaru saddled with a debt she cannot easily escape. To make her repay what she owes, Masamune forces her to join his survival game team, Toy Gun Gun, much to the dismay of Tooru Yukimura, the group’s other member. What begins as an unwelcome arrangement slowly pulls Hotaru into the fast-moving world of survival games, where teamwork, reflexes, and strategy matter as much as determination.
As Hotaru trains with the team, she learns about Toy Gun Gun’s dream of winning the Top Combat Game (TCG), the tournament that decides Japan’s best survival game team. Her lack of experience, the team’s rule against female members, and the fragile balance inside the group make her place there anything but simple, but Hotaru is determined to repay her debt and keep fighting alongside them.