Karuna has a great selection of vegetarian, vegan and macrobiotic treats. This store is also affiliated with the Taiwanese Buddhist temple nearby. I actually went to a vegetarian cooking retreat at the Buddhist sanctuary in Nakatsugawa, Gifu a few years ago.
Prices are fair and the selection is great. I'm a big fan of the mock Unagi (grilled eel) made from mashed tofu, lightly fried on a sheet of nori and seasoned with unagi style sweet soy sauce and sansho.
Only problem is, Karuna is quite a way from downtown Nagoya. A long train ride is required and then a hike up a long hill. If you go by car there are only two or three parking spaces. Be careful!Pros: Fair prices, good selection, Take away bentos and sandwiches
Cons: Out of the way, Online shop shipping costs rather high