Trust me, if you go to Japan you will go to a 7-11 whether you want to or not. They are absolutely everywhere, like “ubiquitous” is an understatement. I think when we were there we went to 2-5 convenience stores per day just because they were just so… convenient…
Local options are always better. The Mexican joint sells you a massive breakfast burrito for $6. Nepalese takeout will feed you for days for $16. Hot dog truck will fill you up with delicious processed meat for $4.
Subway? Subpar lunch made out of cardboard and ground up yoga mats for almost $20.