Supermarkets are harder to find - it seems like a lot of Japanese live from a combination of convenience stores and ordering online. You’ll probably have to look up a nearby supermarket if you want to find one - they’re there, just not so common.
Budget tip Cook in your hostel to save some money. Buy some simple ingredients (tomatoes, eggs, bread) and make a simple diner. The eggs and bread could also serve as breakfast the day after. Total cost: 350 yen for eating twice. Not bad!
Price of fresh food
Vegetables, fruit and fresh food (fish/meat) tend to be expensive. Some fruits that are very common in Europe such as peaches have a highly inflated price (1000 yen) in Japan. It’s fun to find a local food market and see all the weird things they sell - from fresh squids that are still alive to the weirdest looking fruits and all kinds of herbs and soices.