Toshiya is a character that is featured as a friend and rival of Gorou. Gorou befriends him at 5 years old and teaches him baseball. He is a serious and intelligent character with a great love for baseball. His position is catcher.

When he is abandoned by his parents at the age of 11 and taken in by his grandparents, becoming a professional baseball player becomes his goal, something he starts to chase after ruthlessly. Toshiya has a warm character and he values his friends dearly, he has a high but realistic opinion of Gorou. On the field however he has a cold and manipulative personality which puts off his opponents and makes him a very difficult person to play against but as a teammate he is more then reliable.

In MAJOR SECOND Season 2, he's the manager of the national team.

His weak point is his tendency to think too much which causes him to get bouts of depression at times. A tendency that puts him opposite of Gorou which is one of the things that makes them such a good battery, when they form one. During the series, Toshiya and Gorou are more often opponents then teammates.