Racism is present in Japan, the comment that spawned this subthread appeared to be dismissing it as something that had absolutely no explanatory power in this phenomenon and further seemed surprised by Japanese racism as a concept.
Here’s the Wikipedia article.[0] Japanese (the nation) citizens of non-Japanese (the ethnic group)[1] suffer discrimination, particularly the indigenous peoples (the Ainu just got formal recognition a decade ago) and people of backgrounds Japan (the nation) has had historical enmity with (Chinese, Korean).
Whether or not we can parse specifically what portion of kids not wanting to go to school is due to this, the fact that 30% of non-Japanese ethnicity respondents of a poll conducted by the Justice Ministry said they had experienced hate speech and 40% said they had faced housing discrimination[2] seems like it would absolutely have an impact on the school experiences of those children.
This is all limited to the types of racism that are pervasive in Japanese society that a broad portion of the student population may have experienced, but Japan’s particularly strong anti-black sentiment is also notable when discussing racism in Japan more broadly.
As to why this might be a particularly strong factor in Japan, as opposed to being some sort of “cosmic background racism” present everywhere, Japanese people’s self-conception of Japan is very tied up in ethnic identity in a somewhat unique way (maybe the prevailing sentiment of Jewish people living in Israel is somewhat similar).[3] Government officials used to talk openly about one culture, one race—when Japan has never really been that and is becoming less so with time. 10% of Tokyo is foreign born, to say nothing of those who were born in Japan of non-Japanese ancestry.
I talked to a guy who was ethnically Korean, but was nationally and culturally American, and who lived in Japan. Knowing something about the Japanese attitude toward Koreans, I asked him if he experienced any prejudice in Japan. He said no, and that he thought the prejudice was not racial, but rather against the culture.
