He seems to be of mixed-ethnicity, as his first name is English but his surname is Japanese, and his company, Tobioka Conglomerate, is stated to be based in the United States but deals with the more typically Japanese subject of robotics. It is likely Michael is a Japanese-American.
As a wealthy businessman, he seems well-groomed and dressed, and appears a bit smug. However, he actually holds no ill will towards Kunio or any other athletes who compete against him, and in fact, appreciates their input in his designs.
Something of an amusing oversight in the game is that when a player wins the final level of the game, a cutscene plays with Tobioka celebrating that someone has arisen that can beat his team...but the same cutscene plays unaltered even if you beat the game playing as his team!
Tobioka is a playable character in River City Melee Mach!! as an Edit character.