The second series is to follow the events of the second video game, focusing on the lost continent of Mu. The ancient civilization vanished ages ago, and a few of its remnants still exist as myths and legends called UMAs (unidentified lifeforms). The UMAs begin merging with humans in order to search for the treasures of Mu, the powerful ooparts, which will give 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 new forms, including Thunder Berserk, Fire Dinosaur, and Green Shinobi.

Heroman specials released in DVD/BD volumes 2, 5 and 8.

The story tells the story of a blood-red moon suddenly appearing in the sky, which is known as the red moon event in history. The remaining survivors had to hide in the city protected by high walls. Among the survivors, some people also suffered from mental mutations. Among them, those who could not control their own mental mutations would emit mental plague and radiation. It contaminates the normal people around it and poses a great threat to the surviving humans. In order to solve the source of the pollution, High Wall City established a special pollution cleanup department, recruiting people who can control spiritual energy, and our protagonist Lu Xin is applying for the most dangerous cleanup department!

Habahiro Hige awakens at his desk at work, but much to his surprise, he has become a baby! To make things stranger, Iori Wakabayashi walks in wearing a school uniform but doesn't recognize him as the baby. Upon being picked up and held by her, Hige discovers that he doesn't just have the body of a baby but the mind of one as well.