[hamandcheese]

Do those alerts work for foreigners on data-only SIMs?

[jen729w]

Yes. My partner got one in Morioka about 6 weeks ago.

Edit: very, very quickly after the quake, which we felt, I might add. I got a notification via the 'Safety tips' app long after. I think I was on Airplane mode at the time.

[rdl]

Unclear. I have a t-mobile e-sim in the phone I was using and that worked for me.