Short car driving insurance for non-residents

Hi, I'm going to stay by a friend in the countryside, so I asked her about borrowing a car, which she said was ok if I get my own insurance, and hers doesn't cover other drivers.

I see in this article it's quite frequent to do that in Japan https://mainichi.jp/english/articles/20170718/p2a/00m/0na/010000c but I wonder if any of those insurances will cover a non-resident with an international driving license ?

Actually, before I had seen one offer where it's was done with an app requiring a local phone contract, but I just now see in the article they say it's available at convenience stores too.
The trouble is the people at the convenience store are certainly completely unable to tell if it's acceptable when you have an IDP / are on a tourist visa, I'd better check with the insurance company (even if it will likely say no).