It has been a few years since Chase disappeared and people slowly forgot about the Roidmude threat. However, Heart has been revived! And within him, the cores of Brain and Medic! At the same time, hostile creatures very similar to the Roidmudes are attacking people. Heart thinks, "I don't want to witness Roidmudes clinging to a lost past and attacking people". Out of this desire, Heart volunteers to assist Inspector Otta in the investigations. It is discovered that the people targeted were copy models of previous Roidmudes and Misuzu Hatori, Medic's copy model, is attacked by a mysterious monster. It has the appearance of all the Roidmudes combined and the number on its chest is 5886. Heart deduces the identity and terrifying objective of this monster. However, since he is unable to regain his power as a Roidmude, he is at a big disadvantage. However, Shinnosuke Tomari appears before him...