When Marco Polo’s parents are executed for their involvement in a royal conspiracy, he takes a job as a deckhand to provide for his younger siblings. But one day, a monster attack wrecks his ship, leaving Marco stranded on a mysterious island in Asia.

Not long after that, he’s granted strange powers by a beastly girl who calls him “Master”! This is just the beginning of a cross-dimensional journey spanning time and space, and the fate of the world—including Marco’s family—hangs in the balance!