Japanese Americans in Japan

How would Japanese people treat a Japanese American in Japan? Would they look down on them being Japanese but not being able to speak Japanese?

I wouldn't say looked down apon.

I think you'll be treated just as any other foreigner in Japan.

Being an Asian foreigner in Japan does have problems sometimes as some people assume you are Japanese so expect one to know the proper customs etc. But once it is established that you are not Japanese some leeway is given however it is best to practice and know customs.

I know lots of Nikkei Americans, Canadians and even a handful of British and Australian Nikkeis here.

As above, you are treated like any other foreigner but may be asked where in Japan your family originally came from.

My non-Japanese-speaking Nikkei friends say that people are a bit confused at first when someone speaks Japanese to them and they don't understand, but then they catch on. My Chinese friends say the same thing.

Japanese people are generally polite and friendly and that includes towards Japanese Americans etc.
The only exceptions I have heard of are a handful of students at English conversation schools who refused to be taught by Nikkeis or sometimes any Asian-Looking teacher- they wanted someone who "looks foreign". That is just ignorance though and just a very few people.

As a Japanese American in Japan I have run into very few problems based on my being Japanese American. The only one that I can think of that isn't just a regular foreigner problem is that people expect that since you look Japanese, that you are Japanese and know the language and appropriate behavior for the situation. The biggest problem I run into is that when speaking Japanese I have to speak more fluently in order to be understood than someone with a more foreign looking face. As John said, once people understand that you aren't Japanese then things are more like with other non-asian foreigners.

This can actually be the case for any asian in Japan as Japanese don't necessarily make a distinction between an asian face and a Japanese face.

What people don't seem to talk about much are the advantages of being asian in Japan. You are a "gaijin in disguise" which is a huge advantage. You can be anonymous if you want, and to some extent can pick and choose when to "out" yourself. I've also had people say they are more comfortable around asian foreigners as its a more familiar face.

yllwsmrf, I know exactly what you mean. I am an American of Asian ethnicity myself.

Most people will think you are Japanese/speak Japanese by default.
You don't get people bugging you e at tourist spots (eg students wanting to do english surveys). When I go to a tourist spot with my friend who is of a different ethnicity, they hand him the english language guide, and I get handed the Japanese guide.
So as you pointed out there are many advantages in not sticking out of a crowd.
However sometimes it is a disadvantage as I mentioned because people first assume you speak or know the customs.

One thing is if you want to teach english for example and go for an interview. Asians who are from western countries, Eg Canada, UK, US, I think we
had to do was stress our native ability in speaking English, and identify ourselves as American/Canadian/English etc rather then our Asian ethnicities. So instead of saying "You're Chinese-Canadian" Just say you're "Canadian".