I see what you mean, the thing about food in Japan though is that the minimum quality is pretty high. So I can’t really recommend a specific grocery store, all of the major ones have decent quality ready to eat food that just needs to be microwaved. (They usually have a microwave in the front of the store). Convince stores as well. I’m originally from Australia and so that’s my point of comparison, a convenience store karage bento here in Japan is similar in quality to a Japanese restaurant chain in Australia, but the price is like 1/3rd.

As for actual restaurants, I think the mistake tourists make is trying to find the best ramen or whatever, but the best isn’t going to be that much better than the average joint catering to locals. So in other words, spend less time thinking about where to go and just explore and pick a random place that you like the vibe of, that’s what I do and I’ve never been disappointed here.

I don’t really have time to say all that to every tourists that asks though lol.

Also I’m literally writing this from a random ramen place I walked into, and it was delicious!