I think there are some other areas that have a lot more to worry about than Tokyo. I don't remember for sure, but I think the expected path this time would be north in Yamanashi (I looked into what predictions were when I was house-hunting a few years ago).

“Are there actually any signs of eruption?” said Shinichiro Kariya, a 57-year-old hospital employee. “Why are we now hearing things like ‘10 centimeters of ash could fall,’ even in Tokyo? I’m wondering why this is happening all of a sudden.”

I'm shocked that this is news to anyone. Most schools send kids to a disaster prep field trip at least once where they would cover all this stuff. I guess maybe some part of Japan doesn't talk about it, but there have definitely been TV shows about it, even in the decade I've been living here.