I have many Japanese friends but mostly are people who had live abroad (as exchange student, volunteer, master degrees...). Those stupid racist Japanese people that unfortunately you get into at the streets or public places are very "closed minded" people that were taught since kids to discriminate anything that is not "common or normal" to them.
This is not an excuse, but even between locals there are discrimination issues too! I heard that families that moved from Fukushima after the Tsunami, their kids were bullied by other kids, saying horrible things like: "Do not come close to me! you will get me sick with your radiation!"
My cousins were bullied too! Even though they are 100% Japanese (by ethnicity) but born or raised outside Japan, they were bullied and discriminate as kids or teenagers. If they are "hafu" the things get worse!
I usually hang out with "Nikkei" friends (Brazilian, Peruvian, Argentinian....) and we speak Spanish or a mix of Spanish with Portuguese (something I call "Portunol").
I would like to share an experience:
Once I was dating a third generation Brazilian Nikkei (Nikkei Sansei, who barely look Japanese) and we were speaking in Spanish and sometimes English inside the train. There was a middle aged guy staring at us with a disgust look. I believe my date didn't notice it but I was aware and decided to ignore him. We were standing the whole trip because the train was kind of crowded. When we arrived at Shibuya Station the guy stood up of his seat, bump me hard with his shoulder (almost like a football tackle) and kicked my date's umbrella so the umbrella was thrown out of the train to the platform. The guy didn't say a single word and ignored what he just did, I got furious, chased him and confronted him. The guy was surprised that I speak Japanese and firmly asked what was wrong with him. In a couple of seconds, two securities from the train station came and I explained everything to them. It was a "sweet vengeance" as he had to apologize and I know "losing the face" and being embarrassed in public is any Japanese worst nightmare.
I was so angry that I completely forgot about my date or where she was when I was arguing with the stupid guy, but she was just couple of meters away from the scene, staring me with bright eyes like I was his knight in a shiny armor, defending the damsel in distress.
After that, I had an amazing date!
So I encourage you (guys from TAG) that with those stupid Japanese people who believe they are better than others, just ignore them or humiliate them in front of people, so they will think twice before doing anything racist again.
