These posts are written for Carrie, Pete, and Elvia for their imminent trip to Japan, but of course, anyone traveling to Japan or dreaming of traveling to Japan can enjoy.
This is one of my favorite sandwiches of all time. While you can get it in the deli section of most grocery stores, train stations and the convenience stores definitely sell them, I've found, the best is getting a really good quality one from a bakery.
Tonkatsu is just a pork cutlet. It is served many different ways. In a sandwich, it is usually on crust-less white bread, with cabbage, tonkatsu sauce and a mustard-y like sauce.