Sean Matsuda was born in Brazil, though his paternal grandfather was Japanese. A keen basketball player, his main pastime is martial arts. Sean saw veteran World Warrior Ken Masters in action at the US Masters Martial Arts Tournament and swore to become his pupil.
Ken initially rejected Sean's numerous attempts to impress him, however when Sean told him that he was planning to enter the upcoming third World Warriors tournament, he allowed Sean to train with him. During the tournament, Sean lost to Ken himself. Despite his skill, he lacked the discipline and experience necessary to become a true street fighter. He declined Ken's offer of the US Masters trophy in acknowledgment of how well he had done, insisting that he would win it himself some day. He continues to train under Ken alongside Ken's son, Mel.
He is the younger brother of Laura Matsuda, a practitioner of Matsuda Jiu-Jitsu, a part of his family practices Capoeira, they are: Pedro da Silva (uncle), Enzo and Manuela da Silva (cousins).
Both Ryu and Ken are practitioners of Ansatsuken, which incorporates the most violent techniques from a blend of four styles of martial arts, alongside a mysterious sure-killing technique called