The Last Ninja Yoshitaka Igasaki sends his disciples the Ninningers on a special mission over summer vacation to Shinobigakure Castle to meet its lord Tatsunosuke Hakkaku. However, Lord Hakkaku has been turned into a strange dinosaur-like creature by a strange curse, while Kibaoni Army Corps general Juza Yumihari has arrived in the village as well, seeking its "legendary evil dragon".