This is the subspecies Corvus corone orientalis, sometimes also referred to as the Eastern Carrion Crow, which used to be a separate species (Corvus orientalis).
The Eastern Carrion Crow differs from the nominate subspecies occuring in Europe by its slightly larger size.

1st & 2nd photo: Futaminoura, Mie Prefecture, Japan, 28 September 2018
3rd & 4th photo: Takayama, Gifu Prefecture, Japan, 27 September 2018