Something that is modified or created by the Japanese. Japanetically modified cars are all the range these day, although there may be some adverse health risks due to lack of research in the growth of japanese products.
A person who is Japanese. This word was created because... well, there's no bloody noun form of Japanese, and I need some way to refer to my boyfriend...
The term "Japanesian" provides equal nounage for Japan, so no Japanesian will ever feel as though they are not a person, place, thing, or idea.