Ultraman and his comrades from M-78 (including a new Ultraman, Zero, the son of Ultra Seven) join forces with other allies to fight a massive army of giant monsters led by the evil Ultraman Belial.

At the time between the World Wars, Japan is involved in empire-building throughout East and Southeast Asia. After a brief career as a low-level military adventurer, Iheiji sets up chains of brothels throughout Asia. As Japan's power in the region grows, so does Iheiji's prosperity and patriotism.