I want to note that there was a noisy anti-nationalist contingent, kept at a distance by the police. As a foreigner in Tokyo, with a Korean wife and mixed-race kids, I'd like to thank the anti-nationalists sincerely.
I also want to note that the majority of people in Japan are hugely charming and kind, and that the nationalists are in a tiny minority.
(Footnote: one of the nationalists was doing a particularly bad piece of driving, thereby blocking the traffic. I laughed at him and he tried to explain the situation - that they were protesting against Chinese and Koreans. Somehow as a white person I seemed to an acceptable sort of foreigner, presumably because Japan is in territorial disputes primarily with other Asian countries. I said "watashi no kannae wa Kankoku-jin desu", which is the closest I can get to saying "my wife is Korean", In Japanese. "Abunai", he said - "danger". Right. Tell me something I don't know.)