This is an interesting examination of a racist Japanese comic. Almost the equivalent of Chick tract. As westerner who spent many years learning to speak Japanese and finally studying at Waseda University in Tokyo I understand the frustration of trying to live in Japan and being discriminated against.
There's already huge hurdles for foreigners trying to get housing in Tokyo, you need a Japanese person to co-sign on most apartments. This is something that most Japanese are very hesitant to do, even for close friends. Also there's the issue of "Key Money" which raises the price of entry into new housing even further. Some places will secretly, or even openly, reject foreigner's applications for apartments. The problem many times worse if you're black, Chinese, or any other non-white foreigner.
Many foreigners will speak of the "gaijin bubble" when on trains or in restaurants, the space that surrounds you even on full crowded trains. Most of my friends explain this as being a consequence of Japanese people being embarrassed of their English skills. Even if this is the case it's incredibly alienating for someone trying to live in a new country.
Bars (izakaya), restaurants and hot springs are notorious for foreigner discrimination and the further you get from Tokyo or Osaka the worse it gets.
Newspapers frequently play up the threat of foreign crime when the in fact statistics show that most crime is caused by Japanese and the percentages mostly follow the population percentages. Fortunately the newspapers Asahi and Mainichi have gotten better over the last couple of years.
The last thing to remember is that Japan doesn't offer the same services many other nations provide for the poor. Homelessness and mental health aren't supported in the same way they are in other nations. Anyone who has been to either Yoyogi or Ueno park in Tokyo have seen the results of this in the blue tarps and homeless communities without any formalized shelter or mental health services.
That said many Westerners come into Japan with notoriously insulting attitudes and it's important to stand up to them and tell them how stupid they're acting. The attitudes of "Otaku" that come to Japan only equipped with knowledge of out of date manga and anime who speak Japanese gleamed from these sources often come off purposefully sounding gangster like. Many gaikokujin men's attitudes about Japanese women are appalling.