Inspired by Celestial Maidens from Korean myth and pitched as Final Fantasy meets Castle in the Sky, an amnesiac sword-for-hire and a theatre troupe performer with mysterious powers discover that their destinies will change the fate of multiple worlds.

Ex-soldier Sunho lives in the Under World, a land of perpetual darkness. Two years ago, he woke up without his memories, in possession of just his name and his sword. Now he does odd-jobs to scrape by, until he comes across the score of a lifetime - a chest of coins for anyone who can hunt down a girl who wields silver light.

Ren is a cheerful, spirited acrobat, travelling as part of a theatre troupe with her adoptive family. But everything changes when they are attacked by a demon. In fear and rage, Ren releases a blast of silver light and kills the monster - but cannot stop her beloved uncle from being grievously wounded.

Determined to save him from succumbing to the poisoned wound, Ren sets off over the mountains, to where the creature came from - and from where Ren fled ten years ago. Her path sets her on a collision course with Sunho, but he doesn't realize she's who he is looking for. As the two grow closer through their travels, they come to realize that their pasts - and destinies - are far more entwined than either of them could have imagined . . .