Short answers, pulled from the story.
Toshi Sadamoto created Sean Matsuda as a headswap of Ken Masters to fill an empty slot during development in 1997. Kinu Nishimura designed just the face for this new character while keeping the body identical to Ken.
The team needed an empty slot filled immediately to meet their release schedule during development in 1997. The process was rushed and born from necessity rather than creative vision.
He stands 175 cm tall wearing a yellow karate gi with a black belt and red fingerless martial arts gloves. His ears remain pierced and he has vertical dreadlocks on top with shaved sides to his head.
Sean Matsuda watches Ken Masters perform at a local tournament in Brazil where he develops an interest in martial arts. His grandfather Kinjiro teaches him traditional Japanese jiu-jitsu while his uncles practice capoeira.
Rafael Arrivabene and Richard Perassi analyzed Sean's portrayal to observe that defined as Brazilian, he was portrayed through American imagery like his red white and blue basketball. They noted his fighting style appeared exaggerated and comical yet incomplete within academic frameworks.