"There was once a nation that killed the ones they summoned, only to find that summoning ceased to succeed thereafter. Thus, I shall let you live and return. Be grateful for the noble sacrifices of your predecessors."
Hayato Kumakura, who was summoned to another world three years ago, was sent back to Earth after the demon lord was defeated.
But on Earth, zombies had been appearing for the past three years.
Hayato, who possesses the abilities of a transmigrator, dominates in a world overrun by zombies.
