What are the most popular dishes in Asian culture, specifically Japanese?

Rice, Miso-soup, Grilled fish, Natto and Otsukemono.

In Japan.

Where exactly did you hear about these highlights? I know several parts of America that don't even serve burgers and several party of Italy that don't serve pasta. With Asia, it's the same thing. It depends on the location and external influence. For example, in New Orleans in the US, the food is heavily influenced by the Caribbean and the French, and not so much by the "burger and fries". Same thing with the west coast.

Most popular in Japan? I've heard it was KFC. Many families see it as a dine out experience, especially on Christmas. If true, the most popular dish is fried chicken.

The combination of steamed rice, miso soup and some picked veggies ("otsukemono" as Takuya says - it means picked veggies) is the base of Japanese everyday meals.

japanese food has to be typified by teppanyaki and tempura. google them. asian food on the whole is built around rice.