One Piece is property of Eiichiro Oda
The song is Wizard Love amazingly performed by Meekakitty and Heyhihello
On a side note, not a fan of the Zoro Nami pairing, but I thought it would work for this song. Haven't really given much thought about the Robin Luffy either, I wanted to put Robin for Slytherin, but it did not seem quite right for the lyrics.
