Upon starting middle school, Yuri Otani reluctantly becomes a member of the 'Alien Party,' a determined group dedicated to capturing any alien trespassing on school premises. Battling a lifelong fear of aliens, Otani is far from enthusiastic, especially when paired with a 'Borg'—an alien-like protector. Despite her initial apprehension, she discovers comfort in her comrades: the self-reliant Kumi Kawamura and the clever Kasumi Tomine. With roller blades and lacrosse sticks in hand, the Alien Party faces off against extraterrestrial dangers, questioning whether their tools are sufficient for the trials ahead or if their fears will lead to a devastating defeat.