Ten years earlier, Princess Krystal Novaty "Hime" Nokanatika fled her native realm to evade lethal schemes from a malevolent faction. Upon landing in contemporary Japan, she meets Haruto Satou. Together they forge a pact: he must erase the sight he has just seen, and in return they will form an alliance. As she prepares to journey back to the Nokanatika Kingdom to assume her sovereign responsibilities, Hime says goodbye to Haruto. Yet when the young man suddenly recalls their initial encounter, he hurries to the spot where she first manifested and steps through the interdimensional gateway to reunite with her.
His presence interrupts the nuptial ceremony between Hime and Prince Marmarugias Gisaras. The wedding is violently halted by an abyssal beast that endangers the princess"s life. In a spur of instinct, Hime swaps rings with Haruto, bestowing upon him radiant abilities that enable him to vanquish the creature. Now known as the Ring King, Haruto must wed four additional princesses to gain further mystical powers and stand a chance against the world"s ultimate foe: the Abyss King. His resolve is tested as darkness looms forever.
