I voted for "who knows?", but I would like to think that it will never happen.

It doesn't seem possible to me from the circumstances they have in Japan; having the US military bases on the land is one of the good reasons to make it difficult for Japan to do such an inhumane thing; another thing is that the foreigners are spread out all over Japan, not like they used to live in certain parts of the country, which makes it hard to even think the massacre is physically possible.

Ordinary Japanese people are not armed including the Tokyo governor Ishihara Shintaro, hopefully. They neither know how to use weapons, nor how to fight back when they are pointed with weapons.