So much that I love. Where can I begin?
Okonomiyaki! I miss it so much! I prefer kansai style over hiroshima style, but they're both great!
imoten - tempura-fried sweet potato that I used to get all the time. I also liked to get yaki-imo in fall and winter.
ten-zaru - zaru soba with tempura - the combination of hot and cold is great!
Japanese-style amaguchi curry - I don't like Indian curry very much, but sweet Japanese curry isn't spicy at all and I love it. fortuantely I can get it at the Japanese grocery store here
gyuudon - something people in Japan probably miss too
oden - I love the egg and the konnyaku and the tofu and the chikuwa and almost everything (almost...)
kani-cream croquet - yummy! crab and creamy white sauce
sea-chicken onigiri - sounds disgusting, canned tuna with mayo in a rice ball, but I got completely addicted to the ones you got from the convenience store.
Katsuo-tataki - Kochi speciality. Katsuo is out of season most of the year, except in Kochi it's always available. Katsuo-tataki is katsuo (like a small tuna) lightly grilled on the outside with the inside still raw, cut like sashimi, and served with a garlic soy sauce.
snacks like warabimochi with kinako and ohagi (like daifuku turned inside-out) - you could get good ones from the specialty tea shop
mont blanc (momburan) - creamy chestunut cake-like dessert, so good! and at my favorite cake shop they made the BEST yonashi tarts and mousse cake! So amazingly good. and the cream puffs! There used to be lines of people waiting to get the cream puffs as they came out on weekends, that's how good they were. They had both whipped and custard cream in them, dusted with powdered sugar, as big as your fist. Made fresh throughout the day. Amazingly good. Not really Japanes food, but it was a specific Japanese bakery (not part of a chain either) and I miss it.
Melon soda - there's something initially disturbing about electric green anti-freeze colored soda, but it's so good, especially when it was topped off with vanilla ice cream and a marachino cherry (cream soda... yum).
edit: just thought of something else - bottled tea! I don't mean the regular green tea and oolong tea that you can get, I mean the stuff like soukenbicha and juurokucha. I don't know what's in them, but I used to drink them constantly - there's something addictive about them. Can't get either of those at my local Japanese grocery. I haven't had them since I visited San Francisco last year. Spare some Soukenbicha for a poor girl down on her luck desperate for a drink? I need a fix!!