Hajime Ichinose"s everyday existence takes an unexpected turn when a divine figure named J.J Robinson presents her with a tiny tome titled NOTE—a tool that turns her into one of the Gatchaman, the famed guardians of Tachikawa City. Emphasizing that their organization must stay hidden, fellow Gatchaman Sugane Tachibana escorts Hajime to their headquarters, where Paiman, the panda‑shaped extraterrestrial leader of the Gatchaman, explains their mission: to eradicate alien threats that endanger humanity. These existential dangers, known as MESS, grow ever more perilous, annihilating all they encounter. It is now the responsibility of the Gatchaman and their newest member to halt them before global chaos ensues.