For a long time I've thought about creating a guide to the intricacy that is Japanese cuisine - especially since there is so much food out there that many foreigners haven't heard of. So whether you're stuck in some dodgy alley in Harajuku and aren't sure exactly what you ordered, or you're in London and trying to impress a friend that's visiting you with how culturally diverse you are, here's a (hopefully appropriate) guide:
Edamame 枝豆 (v)
Appetizer. These are literally soy beans - they're actually quite delicious and very healthy. They come in pods and you just eat the beans and put the pods in a bowl they give you.
These usually come with pork meat in them, but I have seen the vegetarian version of them as well. They're practically dumplings - they're fried at first and then you put water in the pan and boil them. Can be had with soy sauce (as almost everything in Japan). When ordered, generally come in 4 or 6 pieces.
You will notice often in Japan certain obsession with flavour - and nothing beats green tea. It's a bit of an acquired taste, macha (or green tea) ice-cream, but it's definitely worth the try.
Mochi 餅 (v)
A traditional Japanese sweet, a rice cake. The texture is quite soft, almost gooey. They can come with fruits inside, or other flavours, and should be eaten on the day when you buy them or in a few days tops. They harden after a while and aren't meant to last.
These are the equivalent of the Chinese buns (baozi, 包子), made from flour dough and with meat inside, almost invariably minced pork. Often sold in train stations or as street food, steamed in those huge baskets, they can come in very big sizes and are quite tasty.
"Grilled as you like it". Best experience for this is (and typically how it works in Japan) is a restaurant which has hot plates, or grills, at each table. Or, more like it, as each table. The toppings and batter vary according to region. In Tokyo the batter will most likely be cabbage, eggs, green onion, a variety of veggies, and then can include pork meat, seafood, rashers on top. You mix the batter, then put it on the stove to cook. Once done, just add a few sauces on it.
Ochazuke お茶漬け (v)
Or chazuke. This is one of the few dishes I don't like. Basically rice with some topping (can be vegetarian, or meat or raw fish) on which you pour green tea.
Also known as heaven on earth. Noodle soup dish which can come with boiled eggs, meat and a variety of other toppings. Many places let you add as much of the topping as you want (for extra money). Broth can be either soy based or miso based, and is generally made with either chicken or cow bones (cooked for several hours). Some places also offer you free chili sauce, chili powder, fresh garlic to crush, sesame seeds to add. Ramen shops are one of the main attractions for drunk Japanese people.
Raw fish or seafood. Just the fish (or seafood). Dip it into soy sauce. It needs to be very fresh as well - otherwise it starts smelling (note: fresh fish is not supposed to smell. So if it does...). The names then depend on what you want: salmon (sake), squid (ika), shrimp (ebi), tuna (maguro), mackerel (saba), octopus (tako), yellowtail (hamachi), puffer fish or moon fish (fugu), scallop (hotate-gai), sea urchin (uni), whale meat (gei-niku).
Soba 蕎麦 (v)
Soba literally means "buckwheat". So guess what - thin buckwheat noodles. They can either be ordered "cold" - which means noodles and a dipping sauce - or "warm" - in which case they come in a soup. I have rarely seen them with anything else besides the soup or dipping sauce, but the dipping sauce can sometimes contain meat.
This is the sashimi + rice. The names remain the same, so if you want salmon sushi you just say "sake sushi". In most places, you can dip the sushi in soy sauce and have extra wasabi (that green paste made of Japanese horseradish) to put on it should you want. Some high-end sushi restaurants (like Sushi Mizutani) will not let you do that - as the cook puts the exact amount of wasabi and has a special soy paste he applies to each piece. Also comes with vegetarian options, albeit limited, like "kappa sushi" (with cucumber. Kappa doesn't mean cucumber, it's actually a sea goblin from folklore).
Japanese cake shaped as a fish. Generally filled with custard or red bean paste, but often places have a variety of fillings, including chocolate or cheese. They are baked in a special mold on the spot.
Japanese ball-shaped snack. Made with wheat-batter and often containing diced squid (or meat).
Tempura 天ぷら (v)
Most often vegetables or shrimp covered in batter and deep fried, but can also be fish. They have a special dipping sauce for tempura. Batter is meant to be crisp and the whole dish needs to be quite freshly cooked. Some restaurants have a bar where you sit and have your tempura put right in front of you just as it is taken from the deep fryer.
Breaded deep fried pork cutlet. Can come with a few sauces (tonkatsu sauce or mustard) or salt (in which to dip). There are two types of pork used: fillet (hire) or loin (rosu). Generally served with shredded cabbage.
Related somewhat to ramen, however the broth is fish based and the noodles are much thicker. Can often be ordered plain, or some varieties such as poached egg which then breaks and colours the whole soup.
It should be noted that Japan is a very diverse country geographically and culturally - as such these dishes can be very different in different parts of the country. Dishes marked with (v) stand a good chance of having a vegetarian version of it on the menu but often can also be found with meat.