Satou, an ordinary male student, was unable to confess his love to his childhood friend, Hime, but one day she suddenly announces she's moving far away. Satou chases after Hime and follows her through a gate of light into another world known as Arnulus!

Satou visits Maasa, the Land of Water, and unexpectedly ends up marrying Saphir, the Ring Princess. Saphir believes she needs the Ring King's power to save her homeland from being controlled by the Gisaras Empire.

Satou and his friends have arrived in Satou's world with no way to return to Arnulus. Satou suffers from being unable to fulfill his duty as Ring King when Amber, the Ring Princess of Idanokan, the Land of Earth, appears before him.

Satou and his friends return to Arnulus among countless corpses of imperial soldiers and monsters. Satou encounters the Abyss King in a hopeless situation. Using the Ring Princesses' power he challenges the Abyss King in a confrontation to save Arnulus!