The Japanese marten is omnivorous, preferring meat from fish, frogs, and small birds and mammals, but consuming insects, fruit, and seeds when necessary.

[2] The two confirmed subspecies of Japanese marten are: It is most closely related to the sable (M. zibellina), with which it is sympatric on Hokkaido.

It has been recorded in South Korea, but no locality details prove a wild origin and no native population has been confirmed.

As it is a mammal, the female produces milk for her young offspring, but by 3–4 months of age the kits are able to hunt, and they soon leave their mother.

They tend to choose well-established forests because of the ways the creatures have specialized[clarification needed] and due to their long lifespan.

Many fleshy fruits rely on birds and bats to disperse their seeds; however, in more northern climates, the numbers of these species decrease.

As a positive, the martens prey on Japanese hares (Lepus brachyurus), which lower the quality of trees by their browsing.

[2] The biggest threat to the Japanese marten is the logging industry, which targets its preferred habitat of well-established forests.

The industry often clear cuts forests quickly destroying the creatures habitat without allowing it to recover.