Thousands of years ago, the great dragon Bahamut wreaked havoc on Mistarcia, a planet where both gods and demons coexist. Working together to save the world, the warring deities narrowly managed to seal Bahamut, agreeing to share the key between them so that the dragon would be imprisoned forever. With the world secure from Bahamut's annihilation, bounty hunters like Favaro Leone may go about their job as normal. The amoral Favaro lives a laid-back, self-serving lifestyle while on the run from fellow bounty hunter Kaisar Lidfard, a virtuous man who swears revenge on Favaro. However, Favaro's carefree existence is upended when he meets Amira, a mystery lady who possesses half of the fortune.