Aburage is deep-fried tofu. Takuan is yellow pickled daikon radish. All these products are available in Japanese stores. To prepare powdered wasabi, mix with water to a thick paste. Let stand, covered, a few minutes to develop flavor.
Prepared wasabi is also available in small tubes.
Prepare ingredients before guests arrive. Place the rice in a large, shallow serving bowl. Place the yakinori in a pile on a plate where it will stay dry. Arrange other desired ingredients attractively on platters. Set out a separate small dish of wasabi, another with pickled ginger, and a soy sauce pitcher or individual dishes of soy sauce for dipping.