Since you are in Kyoto I think you should contact
Good Samaritan Club or one of the other (free) volunteer guide organizations and ask them to take you around a grocery store.
Or try to find some local clubs (hiking, toastmasters, etc.) and make a friend or two who can help you.
You can eat tofu as is. Just put a little soy sauce on top of it. Note there are various kinds, different textures, creaminess, etc. That, with maybe a little rice and some sliced takuwan (the yellow daikon pickle) on the side, you have a true Japanese meal.