Some time has passed since the Mt. Minakami incident. X-Day has already taken place, leaving Cronos the rulers of the world. A year after the events of X-Day, life seems normal other than the fact that Zoanoids are among the population. Tetsuro, Mizuki, Yohei Onuma, and Shizu Onuma are in hiding in an apartment, unknowing that Aptom is watching over them. They begin to doubt Sho is still alive. Balcus is working on a particular Zoanoid to defeat Aptom.