Fagus japonica, known as the Japanese beech, Japanese blue beech or in Japanese as inubuna ("dog buna") or kurobuna ("black buna"), is a deciduous tree of the beech family Fagaceae.

The simple leaves are arranged alternately along the branch.

They are slightly pubescent and slightly glaucous beneath, with 10–14 pairs of lateral nerves.

Fruiting peduncles are 3–4 cm long and glabrous.

[4] It is endemic to Japan, where it is one of the main tree species in natural deciduous forests particularly on the Pacific side of the country.