Long ago, powerful beings known as Aptitudes roamed the earth, each of them able to control their own separate element. Due to opposing elements and disagreements, four dangerous disputes appeared between 8 Aptitudes. To protect the people from their fights, they escaped to their own realms and left behind magical rings that a holder could use to settle the disputes for them. In present-day time, we follow the main character, Mercury Lo, who is a hyperactive secret agent that's terrible at his job. He is tasked with preventing a gang of assassins and thieves from stealing a ring from a museum - little does he know that he's about to be tasked with a greater job - helping free the Aptitudes of their disputes and bringing them back to the Earth they once roamed.