It's possible that you're thinking of:
* Canis lupus - This is the scientific name for the gray wolf, which is a species found in many parts of the world, including parts of Asia. The name "nipponicus" might be an attempt to specify a particular wolf subspecies found in Japan, but there is no recognized subspecies of gray wolf with that name.
* Canis familiaris - This is the scientific name for the domestic dog. While there are many different breeds of dogs, there are no recognized subspecies within the domestic dog.
It's also possible that "Canus nipponicus" is a made-up or informal name.
If you can provide more context or information about where you encountered this name, it might be possible to determine what it refers to.