My fiance and I met his coworker at Ryoko last week. It was a cute little hole-in-the-wall place with good sushi. I enjoyed dinner and the staff was very nice. The only con is that it's in a basement between Union Square and a not-so-nice area, so bring a friend, as you might have to park far away (BART is nearby, as well).
Pros: good sushi, friendly staff
Cons: basement atmosphere, difficulty parking
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