Mikawa Province was an old province in the area that today forms the eastern half of Aichi Prefecture. Its abbreviated form name was Sanshū . Mikawa bordered on Owari, Mino, Shinano, and Tōtōmi Provinces.

Tōtōmi Province was a province of Japan in the area of Japan that is today western Shizuoka Prefecture. Tōtōmi bordered on Mikawa, Suruga and Shinano Provinces. Its abbreviated form name was Enshū (遠州). The origin of its name is the old name of Lake Hamana.