I know this thread is extremely old, but in case anyone comes to this page looking for vegetarian sushi, I recommend Shojin. This downtown L.A. gem is the best vegetarian Japanese restaurant I've ever been to. Even my carnivore friends leave here happy and full.
All of the appetizers, salads, sushi and desserts are amazing. The Lemon Eryngii Mushroom & Asparagus is my absolute favorite dish here; it's so buttery and divine. The Shiitake Mushroom Tempura is another favorite. I would skip the orange "chicken." If you are not a vegetarian, the fake chicken won't be up to par, although my vegan friends liked it.
If you ask for "just water," you get a free bottomless jug of Fiji bottled water (I saw them refilling it) with sliced strawberries, citrus wedges or mint leaves in it.
Full menu with gorgeous pictures: