Just came from a dinner at O Shima. We found out about it through one of the deals at Groupon (or similar). It was easy to locate. We came at shortly after 6pm so there was parking right outside of the restaurant on 17th ave.
We ordered a miso soup each and a party plate to share (only ate half of it, the rest took home). One of the best sushi places in Calgary I've been to. Super fresh and tasty rolls, relaxing atmosphere and good service. I think that if not for party tray, the service could have been faster. Great experience overall and will definitely be back.