Taichi Nishimura and his childhood friend Rin Azuma are pulled into the fantasy world of Altia when a magic circle appears beneath them on the way to school. At the local Adventurer's Guild, Taichi registers as a rare Unique Magician with the power to summon elemental spirits, and Rin as a Quad Magician who commands all four elements, a level of power the world has never seen. They take up adventuring, unaware that a shadowy figure orchestrated their summoning for its own ends.