Maco 

Mako is known in Japan as Ryouta Kajiki. Yugi and his friends meet Mako after Joey and Tristan begin to eat his fish, without realizing that said fish belonged to someone. Mako is an "ocean duelist", due to the fact that his deck consists of underwater creatures. Shortly after meeting Yugi, he challenges him to a duel, using his underwater creatures to catch Yugi off-guard. During the course of the duel, Mako tells the story of how, as a young boy he was fishing with his father, when a huge storm kicked up. His father, who took the time to secure Mako to the mast to ensure his safety was himself washed away with the storm. After washing ashore, Mako noticed that their life boat was missing. He reveals that he's competing in the tournament in order to buy a boat, so that he may search for his father. In the end, he loses to Yugi, but vows to keep trying. - MelMel