singular or plural?

[teleostomi]

Mt. Fuji sits at the border between Shizuoka and Yamanashi prefectures.

Does "prefecture" have to be plural in this sentence?

[oishii]

Mt. Fuji sits at the border between Shizuoka and Yamanashi prefectures.

Does "prefecture" have to be plural in this sentence?


Yes, since you are referring to both prefectures.

A more simplified example.

It sits on the borders of both countries.


.

[danmahaffey]

Fujisan sits at the border between Shizuoka prefecture and Yamanashi prefecture.

We can collect both prefectures and roll them into one word. Like the blue, pink, and yellow boxes = the blue box, the pink box and the yellow box.