Neo Arcadia - Yami ni Saku Niji

Long ago, the world below was swallowed by an impenetrable darkness. From his celestial domain in Heaven, the King of Light harbored a grand ambition: to forge a radiant nation upon the shadowed earth. To achieve this vision, he dispatched his royal son, Rain of the Rainbow, on a mission to confront Ebb, the formidable King of Darkness. The King of Light expected his son to bring illumination to the land, but fate had entirely different plans for the two rulers. Upon their meeting, Rain and Ebb are instantly drawn to one another, falling deeply in love. Abandoning his father's divine mandate, Rain chooses to defy the King of Light. Instead of conquering the shadows, he embraces them, and the two begin living together in blissful harmony within the Kingdom of Darkness. Their peaceful existence seems like a fairy tale born from the void—until tragedy strikes without warning. One day, Rain vanishes completely, leaving behind a shattered paradise and plunging Ebb into a desperate search to uncover the truth behind his sudden disappearance.