The teacher will be dealt with as the story has hit national press and has caused Japan "National Shame". On the other hand, there are thousands of students of Korean and Chinese heritage who get routinely get hassled by teachers and bullied by other students and do not get any press coverage and offers of help from 500 lawyers. Japan is a deeply racist society and there is no internal incentive to change anything unless the "shame" element is brought into play. BTW, the current governor of Tokyo, Shintaro Ishihara, is the guy who wrote "The Japan that can say No" in the 80's (which supported a stronger and more nationalistic Japan which could free itself from the control of America by threatening to sell its military grade technology to the Soviet Union). Ishihara routinely espoused the superiority of the Japanese race and even made comments regarding 'The Bullying Of Asia By The Merciless American Jewish Trio' (he is referring to Albright, Rubin and Soros). By all accounts, he is still one of the most popular politicians in Japan.
Japan is a deeply racist society and there is no internal incentive to change It's not just Japan.
Years ago, I owned a camera store. One of my customers was in the shop, chatting with me. He was a college professor, political science, very prominent in his field, regularly held conferences that dignitaries from all over the globe would attend.
He was born in Korea.
While he was there, another customer came in. He was a very prominent scientist, employed by a world famous chemical company. He was the inventor of a type of plastic that is used in everything from packages to home construction. (I am purposely leaving out clues, but everything I've said is true.)
The second customer chatted with me for a while, and then left. The first customer stood there silently for the duration.
After the second customer left, the first customer walks up, looks me in the eye, visibly tense, and in a very gruff, angry tone of voice, asks, "That man... was he Japanese?"