It is a special bus line called the "Toyota Honsha Line". I don't think it comes with a number. The bus stop should be easily found in front of the station.Here is the official website in Japanese:
http://www.hoei-group.co.jp/bus/toyota.html
The one way trip costs 220 yen. Buses operate only from Monday to Friday and on national holidays, but they do not run on Saturdays and Sundays.
The departure times are shown on the following page:
http://www.hoei-group.co.jp/bus/toyota_j.html
Blue refers to weekdays, pink to national holidays. “y‹´‰w‘O means Tsuchihashi Station.