Mikawa is one of the provinces in JAPAN. It is under the control of the Tokugawa House.
It is adjacent to Owari, Mamushi Oil Field, Shinano, and Tokaido.
For real world reference, see Mikawa Province or 三河国. The Mikawa in Sengoku Rance also covers the western half of Totomi Province (遠江国) of warring states Japan.