Entire books have been written on the etiquette involved in eating a Japanese meal
. Manners aside, though, there are other reasons to play by the rules when you're enjoying sushi that can affect how the food tastes. Here's one: If you're dipping your nigiri sushi (that's the type where a strip of fish sits atop a finger-shaped mound of rice) into a dish of soy sauce, turn it upside down first, so that the tuna, salmon, etc.—not the rice—comes in contact with the sauce. That'll prevent the grains from getting wet and separating, so it'll be easier to eat. Plus, you'll be seasoning the fish, which makes more sense, since sushi rice is already flavored with rice vinegar.