Satou Haruto became the Ring King when Krystal chose him as her husband and gave him the Ring of Light. He and Krystal go way back—they've known each other for about a decade, having appeared in this world alongside someone named Alabaster.
Things got complicated when Krystal had to return to her own world to marry Marmaru-Gias Gisaras, a political union meant to bring peace between the Nokanatika Kingdom and the Empire. Satou followed her through a teleportation gate, showing up right in the middle of the wedding ceremony. An Abyss creature attacked during the chaos, and in that moment, Krystal kissed him and transferred the Ring of Light to him—officially making him the Ring King.
From there, Satou's been traveling around collecting the other Ring Princesses. His core group usually includes Hime and Gramps, though his traveling companions shift over time. Each princess he marries joins him and gifts him her ring as well, expanding his power and his party.
Content compiled by AnimeList.moe from publicly available sources.
