While on her way to a new school, Momoka Sonokawa encounters danger from a molester on a train, only to be saved by a gun-wielding upperclassman, Miou Ootori. Miou, the president of Aogiri Academy's Survival Game Club, sees potential in Momoka's marksmanship skills and persuades her to join. Despite Momoka's initial reluctance, she becomes a member of Sabage-bu, a peculiar club known for its bizarre and extreme activities. Surrounded by eccentric and socially awkward club members, Momoka navigates a world filled with ghillie suits, bungee jumping from school buildings, and unconventional behavior. Through this unexpected journey, the ordinary Momoka must adapt to the chaotic and unpredictable school life that Sabage-bu brings.