Filipina or SE Asian, working where I got my lunch. I could have tried to find more, but I wouldn't usually need to. I got looked at more than usual (not much, downtown), and the few people I spoke with were very nice... Everybody here knows that a huge number of Gaijin took off, and not a few Japanese, either. Shinjuku was hardly the 'ghost town' foreign news would have you think, but at an estimate, one-third of a regular rainy Monday holiday's people were missing.
At my home station, which is on the NE edge of Tokyo, it is even odds that I would see another Gaijin on any day: now I don't. I know of no small number who have taken off, even with their family if their partner is Japanese. I know more Japanese who have stayed, than left. Had a Japanese friend come for dinner last night, who has many foreign friends as he is both a translator and has lived overseas for a few years, and I am his only non-Japanese friend still here. He is contracted to work for a certain bloated Southern US retailer, and the bloated Southerners who work for it fled right away.
If you left or if you stayed, both reactions can make sense. We stayed, and will continue to do so unless we think the food and water is compromised in a scientifically quantifiable way.