Histoire
Momoka's family moves a lot, so she's always "that new girl" and the schools she's attended have all blurred together. Until her first day at Aogiri High, that is, where she's rescued by an armed vigilante, assaulted by a platypus, and coerced into joining a secret organization of gun-toting female commandos. Okay, maybe that last one is really just the school's survival club, but the platypus is real and so are the extremes that club president Miou is willing to execute to recruit Momoka.
Synopsis via AniList (en anglais).