The human realm is under threat from alien invaders in this amusing adventure of fantasy. Enter Don Kurai, the nefarious ruler of "Don Kurai," who has a cunning scheme to gain control. Legend has it that a hero and three artifacts can save the day, but Don Kurai thwarts the quest by snagging one of the artifacts - a copper bell. The other two treasures, a golden spear and a silver shield, are dispatched to humanity's realm as their last hope. Shinnosuke falls prey to Don Kurai's trap and unwittingly creates a portal between the two worlds. However, he fortuitously transforms into the chosen champion of the golden spear. The Nohara family shape-shifts into assorted forms with Mata Tami, one of Don Kurai's team members, aiding their mission. Together, they confront Don Kurai and engage in a fierce battle to rescue their world.