The legend of the Divine Gate is a story told to young children that depicts the merging of the living world, the heavens, and the underworld. "Adapters"—people born with unique elemental abilities gifted to them from the union of these worlds—formed the World Council, an organization which controls the chaos of the Gate by portraying its legend as nothing more than a myth. These Adapters train in a special academy owned by the World Council that allows the students to hone their skills.
Aoto, a teenage boy with exceptional water powers and a tragic past, rejects the offer to join the academy numerous times—until he is successfully pressured by the energetic wind user Midori and stubborn fire user Akane. Together, with the World Council and their mysterious leader Arthur, they seek out the Gate in the hopes of uncovering the truth. But in order to reach their goals, they must unite and overcome their own despair while dealing with behind the scene mischief.