Is Japan a common or proper noun?

* Common nouns are general names for things, places, or people. They are usually not capitalized unless they are at the beginning of a sentence. For example, "dog," "chair," and "city" are all common nouns.

* Proper nouns are specific names for things, places, or people. They are always capitalized. For example, "Fido," "La-Z-Boy," and "New York City" are all proper nouns.