The advanced alien race of the Galactic Bazue Empire is lead to conquer Earth by three offbeat Galactic Generals. One of these generals— General Cassiel, a handsome, young war hero, also happens to be a total sentai otaku. Displeased with Earth's lack of resistance and a sentai team, he briefly calls off the invasion just long enough to secretly kidnap a random group of teenagers and scare them into becoming his "Terra Rangers," Earth's last hope.