In this world, mythical creatures and monsters exist. After a particular incident revealed these creatures to the world, governments from all over the world banded together to eradicate the threat. Most of the creatures were slain in this bloody struggle, while the remainder were either studied or sold into slavery. The single task assigned to the enslaved was to eliminate the last living beings in the world-the ancient gods.

The few remaining gods are currently residing on secluded islands. Each of the five legendary teams that the world government dispatched to the locations was tasked with eliminating the island's gods. A child named Hashi, drafted into this military action by his grandfather, is present on one of those ships in addition to the mythics.