Heisei Mart is a little grocery store in the J-Town Shopping Complex. It sells Japanese items that are difficult to find in other grocery stores.
They have a section near the cash register of items nearing their "best before" date at a discount. They have some ready-to-eat items as well. I loved looking at all the Japanese candies and snacks. Prices are a bit high, but this is to be expected since they have to import from Japan.
If you are looking for a specific Japanese item and can't find it anywhere, I think there's a good chance that you'd be able to find it here.