noun
Kōshin region
Refers to the combined area of the former Kai Province (now Yamanashi Prefecture) and Shinano Province (now Nagano Prefecture). Used in geographical, historical, and administrative contexts.
甲信地方では、冬に雪が多く降ります。
In the Kōshin region, it snows a lot in winter.
Compound of 甲 (Kō, from 甲斐, Kai) and 信 (Shin, from 信濃, Shinano) plus 地方 (region).