Mount Fuji.
Hokusai's "The Great Wave;"
Sushi (which has become so popular, at least in the northeast U.S., that supermarkets have sushi chefs and a small selection of prepared, plastic-wrapped trays of sushi on ice).
Anime, and the cartoon style featuring big eyes.
I'm old enough to remember a succession of attitudes toward imported Japanese products in the U.S.
--1950s: "cheap Japanese imitations."
--1960s: surprise at the high quality of Japanese optical products like cameras and binoculars.
--1970s: the first imported Japanese cars, and surprise that they were not only as good as, but better than U.S.-made cars. People used to argue about whether Ford or Chevrolet was better, now they argue about whether Toyota or Honda is better. Of course all the Japanese companies have built factories in the U.S. so our Toyotas and Hondas are U.S.-made.
--1980s: Sony and Japanese electronics.
Early 1990s: serious concern in the U.S. about economic rivalry between the U.S. and Japan.