The second series follows the events of the second video game, centering on the lost continent of Mu. This ancient civilization disappeared ages ago, with only a few remnants surviving as myths and legends known as UMAs (unidentified lifeforms). The UMAs start merging with humans to search for the treasures of Mu—powerful ooparts—that will grant them the power to revive Mu. After Subaru and War-Rock encounter several unusual enemies, they meet a professor named Doctor Orihime, who sends them on a quest to find the ooparts and stop the UMAs. Using the ooparts, Rockman is able to take on new forms, including Thunder Berserk, Fire Dinosaur, and Green Shinobi.