Buying fish in the supermarket in Japan is a delight, even if the fish is displayed in styrofoam trays, as it is at Life. The most common supermarket fish, mackerel, also happens to be my favorite, and it's sold in a variety of precise quantities. Want three small mackerel fillets? Sure thing. One large? Right over here. Mackerel costs practically nothing and is a snap to cook with the fish grill. I also tried marinated (Spanish mackerel) but skipped the salmon.