Aburaage is one of the soy products. It is thinly sliced and deep fried tofu in short. It’s puffy and has a pocket inside, just like a pita bread.
Inarizushi and kitsune udon cannot be made without it. Thinly sliced aburaage is often used as one of the miso soup ingredients. Japanese vegetarians use it often as meat substitute, because of the rich texture, soy protein, and oil contents. It also absorbs flavor very well.
I think this is a great item to carry at health food stores in the U.S., but unfortunately I haven’t seen it.
You can find aburaage at Japanese grocery stores. I haven’t seen it at Korean stores, even though they often sell already stewed aburaage for inarizushi. Chinese grocery stores have similar items, but they tend to come in smaller size.