Sushi is a very, very delicate flavor. It's not huge. There's no sauce like a butter or Italian tomato sauce. Nothing on it. You enjoy the ingredients. You don't want to have any stronger flavor to kill your palate.
The condiment for the sashimi and the sushi is obviously the wasabi and the pickled ginger and the soy sauce. Sometimes I serve it with the radish, like a thinly sliced daikon radish or thinly julienned daikon radish. So that when you're eating the fish, sometimes it gets too fishy in the mouth, so you want to eat the ginger or wasabi to just clear your palate in between the two different kinds of fish. If you have tune and you're going to go to the next fish, you just want to clear your palate with a little tiny bit of ginger. Then you go to the next one.
That's all that you need. You don't want to eat ginger every time that you eat the sushi. I see that many people put the ginger on the top of each single fish and sushi and eat it. You are tasting ginger but not the fish or anything else. That's not the way you eat the sushi.