A being that threatens the peace of the world and the lives of its people the Calamity Dragon.

Gin, the leader of a unit tasked with exterminating these creatures, carries out subjugation missions alongside Elmer, whom he appoints as his vice-captain. As the two spend their days fighting together, they forge a friendship and trust that transcend the chain of command.

But their bond is suddenly shattered.

What tragedy will befall their unit, and what conspiracy lies hidden behind it…?

The curtain rises on a solitary tale of revenge woven by Gin and Elmer.