I don't know if it's a Japanese thing, if it's unique to Sushi Ota personnel, or if success has ruined their hostess staff -- but getting a reservation and getting service once seating at the restaurant seems to be an afterthought at this place. Unfortunate, because the quality of the food and the imaginative presentation set this place way, way above your average sushi restaurant.
No one comes here for the ambiance. The "decor" is mini-mall. And crowded.
I see some other reviewers have made comparison to Harney Sushi in Old Town. We dined at both restaurants within 3 days. My take: Sushi Ota has better food, and Harney Sushi has better service and decor. Pricing is about the same -- perhaps slightly higher at Harney Sushi.
So I'd give Sushi Ota a full 5 stars if they'd make the dining experience equal to the excellence of their food.
PS Don't even think of coming here without a reservation.