Social restaurant feasts seem to involve sushi these days in my world, the most recent of which was a celebratory evening at Kisaku in the mysterious Tangletown neighborhood near Greenlake.
The group began with a bunch of appetizers, two of which were somewhat appropriate for a vegetarian: edamame and agedashi tofu, which came covered in bonito flakes. When I order agedashi tofu for myself, I'm always careful to specify that I'd like it without the bonito. On this occasion I simply scraped it off and continued to eat the lightly battered tofu.
While the rest of the table ordered platter after platter of creature based sushi, I secured myself a nice little supply of vegetarian goodies: Tofu Dengaku: tofu in a (surprisingly sweet) red miso sauce, a $1.50 Kobachi salad with a scoop of mashed potatoes, and a beautiful Devil's vegetarian role that had an outer skin of marinated, fried eggplant.
It can be tricky with Japanese food to get seemingly meat free options truly free of fish products, but these all seemed to be genuinely vegan (with the exception of the mashed potatoes, which might have had some mayonnaise in them). It was nice to have some unusual options!