Tomoaki Yamaguchi is a Japanese professional baseball player known for his skills as a pitcher. He was born on June 1, 1988, in Osaka, Japan. Yamaguchi has played for several teams in the Nippon Professional Baseball (NPB) league, showcasing his talent and contributing to his teams' successes. In 2020, Yamaguchi made his Major League Baseball (MLB) debut with the Toronto Blue Jays. He has gained recognition for his fastball and versatility on the mound. Throughout his career, Yamaguchi has been a valuable player, earning respect in both Japanese and American baseball circles.