Ryota Kajiki (Mako Tsunami is the English dub) is a duelist that appeared in the original Yu-Gi-Oh! series. He is a fisherman that wanted to win the tournament to buy a fighing boat and become the greatest fisherman in the world in honor of his father who died in a shipwreck (in the dub, he wanted the boat to find his father who may be alive). Mako duels with a water-based deck and duels with honor and even congratulates people who defeat him.
Ryota is a friendly young man but can get easily angered if he catches people trying to eat seafood he caught himself.
He dueled Yugi in a match but ultimately lost. However the two fought greatly and Ryota and Yugi became good friends.
He appeared in Battle City and dueled Katsuya Jonouchi (Joey Wheeler) and lost once more. However the two parted on good terms due to it being a fair match. In the epilogue, Ryota does get his ship.