Japan vs Nipponese

Japan and Nipponese both are nouns.

Word	Noun	Adjective	Verb	Adverb
Japan	Yes	No	No	No
Nipponese	Yes	Yes	No	No

Japan (noun)	Nipponese (noun)
a constitutional monarchy occupying the Japanese Archipelago; a world leader in electronics and automobile manufacture and ship building	a native or inhabitant of Japan
a string of more than 3,000 islands to the east of Asia extending 1,300 miles between the Sea of Japan and the western Pacific Ocean

Japan (adjective)	Nipponese (adjective)
	of or relating to or characteristic of Japan or its people or their culture or language