Grocery Shopping In Japan

Groceries in Japan can be really expensive but if you get to know the grocery stores in your area and how the sales work you can save a lot of money.

Types of Grocery Stores
First off there are many types of stores you can buy groceries in.
Supermarkets- These are the big ones in my area: Maruetsu, Comodi-Ida, Okkasan, Big A, Life, Hallomart, Belix, Tobu Store, Fuji Market, and Itoyokado. Most of these are part of chains. They have different items on sale each day, as well as time sales. The nice thing about these is you can probably look up their chirashi (advertisement) online.
It also helps to figure out what items are cheaper at different stores on a regular basis. For example: most of the stores in my area sell a small can of corn for about 239¥, however Big A sells a larger can for 89¥.
Import Stores- Some of the ones in our area are: Yamaya, Kaldi Kofee, and Gyome Super. These are great to buy canned, dried, ethnic and often breakfast foods at.
Convenience Stores- Convenience stores can be more expensive but we love the Lawson 100¥. We buy our milk, mixed vegetables, bananas, and bread here; just to name a few.
Small Family Shops- These small shops are everywhere and sometimes they have great deals. Some sell fruits and vegetables while others sell non-perishables.
Costco- We love Costco. It is our little piece of America. We usually buy all our meat here as well as our cheese and Peanut Butter. If there isn't a Costco near you then you can use TheFlyingPig and order many Costco items and get them delivered to your house. You can also check out Foreign Buyers Club another import website. I've also used Rakuten to order things like powdered sugar since in the store 100g is is at least 150¥ :(
Time Sales
It took me almost a year to understand time sales. Some stores have sales on certain days at certain times. For example Okkasan has a 77¥ sale once a month where different items are on sale at different times. For example they have a morning sale from 9:00 then some other items go on sale at 12:00 and again at 4:00.
Markdowns
In the evening many stores markdown their meat and vegetables. If you wait around you may be able to find out what time they do this and plan your grocery trip accordingly. You can also look for bread, yogurt, and often pastries with the little percent off stickers, sometimes up to half off.
Well I guess that is about it. Hope that helps. Let me know if you have any questions.