The most famous Japanese food is probably sushi. Japan has so many other great dishes to offer, but for now sushi seems to be most popular. A lot of the sushi we are served in the west is not proper sushi though, it has been Westernised for our palate, most of it coming out of California.
I had a japanese breakfast at a ryokan in Nara in March, 2014.
In Nara I stayed in a small ryokan run by this very nice, old lady. I stayed there for two nights, and even though I had opted out of paying extra for breakfast included, the morning of my departure she offered me breakfast anyway. I had a train journey to Tokyo ahead of me and a good breakfast before leaving would be great.