Chartreuse: the transitional Tōkai–Tōsan dialects (Gifu–Aichi and Echigo), with both Eastern and Western features. Green: prototypical Eastern Japanese dialects (Yamanashi, Nagano, Eastern Shizuoka).
The Tōkai–Tōsan dialect (東海東山方言 Tōkai–Tōsan hōgen) is a group of the transitional Japanese dialects spoken in the southern and eastern Chūbu region. The dialects spoken in the northwest Chubu region are classified as the Hokuriku dialect of Western Japanese. The Tokai–Tosan dialect has three sub-groups: Gifu–Aichi, Echigo, and Nagano–Yamanashi–Shizuoka. These are transitional between Western and Eastern Japanese; which branch of the family they fall in depends on which isoglosses are taken as definitive. (See Eastern and Western Japanese for details.)