Here's a great primer on all the different kinds of Japanese food you're likely to encounter. I am now hungry. Ima skip the omurice tho. Absent from the list is Horumon. Which isn't all that bad if you don't think about it too much. Yes its pretty simplistic and doesn't dive too deep, but that's probably why I'd call it a primer.
While dishes like sushi and ramen have become ambassadors of Japanese cuisine abroad, the local food scene is more crowded and delicious than you might think. With a little familiarity, you'll be able to easily recognize the dishes below. Be sure to try as many as you can while dining out in Japan!