On the all-male planet Tarak, parts-factory worker Hibiki Tokai sneaks aboard a new warship to steal a mecha, only for the ship to be raided by women pirates from the rival planet Mejere. A freak accident fuses the vessels into the Nirvana, stranding Hibiki and two other men among an all-female crew led by the elderly Captain Magno. Forced to cooperate against the Harvester motherships hunting them, Hibiki pilots a Vanguard that can merge with Dita and Meia's Dread fighters.