I had a lot of fun in Japan, and I had a lot of fun eating, but the eating in Japan was not without its difficulties. I can read katakana and hiragana, and I can guess at the meaning of kanji based on my ability to read Chinese hanzi, so sometimes menus in restaurants (or picking items off shelves) was half of a guessing game, half of a hoping that I'd read it correctly.
This meant needing some back ups for times when I wasn't sure what was going on.
My very favourite back up was konbu onigiri / こんぶおにぎり. I developed this obsession with 711s in Japan not only because it was the only place I could reliably withdraw cash, but because rather than the food being fatty and unhealthy like you'd get in Australia, the convenience food (handily, found at the conbini) were bento boxes and onigiri. I love onigiri. With the konbu onigiri there's a slight chance of it containing katsuo bushi, but Anna assured me it was my ever present foe and to continue on regardless.
I managed to get my hands on some baked goods at various points. I found der Akkord in Minato-ku, a totally vegan bakery. From there I supplied myself for the trip home with chocolate mousse, some apple pie, and some flavoured breads. Some of the breads were sour-dough-y, which was a bit off putting, but the mousse and the curry filled breads I had were delicous, and made nice snacks on the flight home. In addition, I was delighted to discover they had a folder, in both English and Japanese, with a full list of all ingredients in all products. In Minowa, I found Cafe Mugiwarai, a tiny vegetarian bakery where I picked up a sultana-filled bread stick to supplement one of my many rides on the shinkansen. Nobody there spoke English but we got by okay.
I became obsessed with edamame whilst I was in Japan. Conveniently it is available everywhere, including ready to eat at supermarkets (but made more delicious by a quick dousing in water hot from the kettle, and the liberal application of salt). Plain tofu was also easy to find, and often I would use my hostel kitchen to whip up a quick tofu scramble for breakfast.
We frequented quite a few shrine and temple market areas, and especially during celebration-y times (such as New Year, when we were there) the stalls will include grilled corn on the cob, basted in plain soy sauce (all the stalls I ate from only used plain soy sauce, though perhaps others used something different). I had not realised until this point how delicious corn + soy sauce could be.
I was able to pick up some other food from floating around the temple markets. There were some snacks and things which were fine, but which I was too full to eat; and in Kyoto I found samosas that were drowned in curry before being given to me. This, incidentally, is a delicious way to serve samosas. And they were pre cut, solving the problem Fi mentioned just the other day.
I suffered some cravings for ice cream, which I sated with frozen fruits, available from the ice cream chests in various conbini.
I would recommend not trusting things just because they look okay. I grabbed some noodles which looked okay, but buried under the noodles and the cabbage were the tiniest shrimps I've ever seen, which was incredibly disappointing. Also disappointing was the meal that came out sprinkled with prawn flakes on the top, waving in the breeze.
At one point, desperate to eat, I resorted to ducking in to a Chinese restaurant that had a television out the front playing Theresa Teng from its speakers, hoping that someone in there spoke Mandarin (they did). Here I was able to eat some vegetables, which were often thin on the ground, it being winter in Japan.
If you're looking for vegan noms around Japan, I super strongly suggest doing some research. Maybe I'd have fared better if my Japanese was greater than a stilted "肉のたべません….わたしわベジタリアんです...", but the research that I did was quite helpful.
Don't trust Happy Cow unless you have a back up plan. Happy Cow worked for me only once (leading me to Otis!); otherwise I was often unable to find places.
I found Cindy and Michael's posts from their 2010 visit to Japan quite useful. I even used it for non-eating things (I took their lead and did the iPod walking tour of Kabukicho and visited the Mori Art Museum, both of which were excellent experiences).
Vegetarians in Japan was a good reference point, though one that I ultimately did not end up using.
A lot of people have heard of Wandering Vegans in Japan, who in 2010 moved back to Australia, but their list of vegan restaurants in Japan is worth checking out.
Survival Guide for Vegetarians (not only) in Japan is also a fairly good site with lots of links and ideas.
Lisa lent me her 2008 version of the Japan Vegan Restaurant Pocketguide which, even though it was arguably out of date was still very useful, as it contained maps and directions. Lisa's Japan tag was also a handy resource.
A summary of my Japan posts:
i: mos burger
ii: roots cafe, hakuba
iii: disney noms
iv: pure cafe, tokyo
v: mikoan, kyoto
vi: ajanta, kyoto (now with added photos)
vii: otis!, hiroshima
viii: vegan healing cafe, shibuya
And that was Japan!