Super String: Marco Polo's Travel to the Multiverse, Vol. 1 - In-wan Youn

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!