Kōshin'etsu (甲信越) is a subregion of the Chubu region in Japan consisting of Yamanashi, Nagano and Niigata prefectures. It is the abbreviation of the old provinces, Kai, Shinano and Echigo provinces. Chubu region, Japan Chūbu (中部地方 Chūbu-chihō) is the central region of Honshu, Japans main island. ... Yamanashi Prefecture (山梨県 Yamanashi-ken) is located in the Chubu region on Honshu island, Japan. ... Nagano Prefecture (長野県; Nagano-ken) is located on Honshu island, Japan. ... Niigata Prefecture (新潟県; Niigata-ken) is located on Honshu island, Japan. ... Before the modern prefecture system was established, the land of Japan was divided into tens of Kuni (国, Countries). ... Kai province (甲斐国; -no kuni) is an old province in Japan that corresponds to Yamanashi prefecture today. ... Shinano (信濃国; -no kuni) is an old province of Japan that is now present day Nagano prefecture. ... The article incorporates text from OpenHistory. ...