I bought my inari tofu at my local asian grocery store, H-Mart. You can find them at most Korean or Japanese grocery stores. I have found that most of them taste very similar so I don't have a particular brand I like. When I buy the store bought versions, I throw away the vinegar packet because I like to adjust according to my personal taste (how sour and sweet). If you're in a rush, you can add their vinegar pocket.