On her way to the first day at her new high school, Momoka Sonokawa encounters a strange woman who brings a pair of guns out at a train molester, only to get arrested herself for possessing firearms. Momoka spots the same woman at her school and follows her to a delapidated building, where she ends up being caught by the school's Survival Game Club. Noticing Momoka appears to have a talent for airsoft, the woman, club president Mio Ootori, attempts to recruit her into joining the club, but Momoka flat out refuses. The next day, Momoka finds herself bullied by her classmates over how close she appeared to be to Mio, but Mio helps sort things out. However, Mio's kindess turns out to be a trick as she drugs Momoka and uses her unconscious body to hand in the recruitment form for joining the club. During the weekend, Mio and fellow club members Maya Kyōdō, Urara Kasugano, and Kaya Gōtokushi take Momoka to an airsoft shop to get her some equipment. After picking out a gun for Momoka, Mio partners up with her for a practise match against the other members, with Momoka's natural talent winning against the opposing team.