My student who was of Korean decent but was the most popular person in high school and went to a good university would disagree with you. As would my friend who was born in Korea, married a Japanese woman and moved to Japan. There is discrimination in Japan, but it's frustrating to see this trotted out time and time again as if you'll be systemically discriminated against no matter where you are. It's just not true.
But if you don't speak Japanese, it doesn't matter if you are Asian looking or not, you won't fit in here. There are lots of other ways you won't fit in here too. Not speaking Japanese well is an absolute deal breaker, though.
Edit: I should point out that there is nothing wrong with the Wikipedia page. As far as I understand what it states is absolutely correct. It's simply that Japan does not have dual citizenship at all. So if you want Japanese citizenship you can have it -- you just have to give up your other citizenship. Japan also does not give citizenship automatically if you are born here. You have to have at least 1 parent who is a citizen. However, you can apply for citizenship and you will get it -- as long as you give up any other citizenship. Otherwise you will essentially have permanent resident status. The latter point is admittedly crazy and it is very unfortunate that many Koreans are born into this situation, but they can fix it by naturalising. They don't want to. BTW, the student of a friend of mine was American and had exactly the same issue. It's not an issue of racism.
But if you don't speak Japanese, it doesn't matter if you are Asian looking or not, you won't fit in here. There are lots of other ways you won't fit in here too. Not speaking Japanese well is an absolute deal breaker, though.
Edit: I should point out that there is nothing wrong with the Wikipedia page. As far as I understand what it states is absolutely correct. It's simply that Japan does not have dual citizenship at all. So if you want Japanese citizenship you can have it -- you just have to give up your other citizenship. Japan also does not give citizenship automatically if you are born here. You have to have at least 1 parent who is a citizen. However, you can apply for citizenship and you will get it -- as long as you give up any other citizenship. Otherwise you will essentially have permanent resident status. The latter point is admittedly crazy and it is very unfortunate that many Koreans are born into this situation, but they can fix it by naturalising. They don't want to. BTW, the student of a friend of mine was American and had exactly the same issue. It's not an issue of racism.