Organic+ was my first real exposure to macrobiotic food (which seems to be quite a thing in Sapporo), conveniently located in the Susukino area. I ordered soy-meat zangi (Hokkaido style fried 'chicken') and whilst it tasted delicious, the serving was pretty small. My (non-vegan) girlfriend ordered the fish, and it took her a while to realise that it was actually mock fish.
The atmosphere of the place was excellent, and the service was good. While the level of English spoken was limited, I was able to confirm that what I was ordering was definitely Vegan, and afterwards they even gave us a couple of Vegan biscuits as a gift.
Cons: Small servings