Koshi Province

was a very old province of Japan in the area of Niigata, Fukui and Toyama prefectures on the island of Honshū.
"Koshi" was also a regional name. It was in what is now known as the Hokuriku region. 
History.
"Koshi" was divided into Echizen, Etchū, and Echigo provinces in the early 8th century.