If you've been forwarded this page by a friend, here's what they didn't tell you. Oshima is the cult classic of downtown Sioux Falls sushi — 109 East 10th Street, half a block off Phillips, in a row most Saturday-night crowds walk right past on their way to somewhere louder. The room is small. The lighting is dim. The fish is exactly what it should be. And the local convention is to call it "the best-kept secret downtown," even though it has 1,081 reviews and a 4.7-star average. That tension between how the regulars describe it and how it actually performs is part of why it's worth writing about.
The orders that earned the rating: sashimi, shrimp crunch roll, soft-shell crab, and the bento boxes at lunch. The sashimi is the move when you want to know what the kitchen is really capable of — clean, cold, properly cut, and not over-iced, which in a landlocked state is the entire point. The shrimp crunch roll is the converter. It's the thing that turns a "sushi is fine" friend into a "let's go back next week" friend. The soft-shell crab roll is the order for when you want to sit at the table for an extra forty minutes. The bento is the one-meeting-then-back-to-the-office order — it lands fast, it eats well, and it doesn't feel like a compromise.
Hours are the first thing to plan around. Oshima is closed Sundays. Lunch runs 11 to 3, dinner 5 to 9:30. The pacing is best on Tuesday at 6 or Friday at 5:15 — Saturday at 7 the room fills up, the kitchen tightens, and the experience drops to about seventy percent of what it can be when you give them breathing room. If you can shift a Saturday plan to a Friday before the first wave, do it.
The buy-two-rolls-get-one-free promotion runs more or less constantly — the kind of standing offer that signals a kitchen confident in its volume. If you're ordering for two people who agree on rolls, you're effectively eating one for free. The free sesame balls at the end are the detail that holds the loyalty: restaurants that comp the dessert without being asked are restaurants that are paying attention to whether you'll come back, and the math on a returning customer is the math the owner is doing.
A note on parking. There isn't much, and the meters around East 10th and Phillips are enforced later than most visitors realize. Plan to walk a block and a half. The reward is a room that doesn't need to compete on volume — Oshima is a small two-tops-against-the-wall room, and the back tables are the seats to ask for.
What Oshima is not: a hibachi room. There is no hibachi at Oshima — that's Tokyo, on South Louise, which is a different mission. If you want a chef performing tableside theater for a group of eight including kids, drive south to Tokyo. If you want a quiet two-top with the right cold sake and a server who answers "what came in fresh today" with the right answer, that's Oshima. Both are excellent. They belong on different nights.
The cooked end of the menu — teriyaki, tempura, the pan-fried bento sides — is fine but unremarkable. The kitchen lives in the sushi half of the menu, and that's where you should live too. If your dinner partner doesn't eat raw fish, the shrimp tempura roll, the cooked-tuna roll, and the chicken teriyaki bento are the safe orders. They won't disappoint. They just aren't where the kitchen's heart is.
If you're new to sushi, order the shrimp crunch roll, a salmon-avocado, and one piece each of salmon and tuna nigiri. That's the introduction. Add the spicy tuna roll if you want a third roll. Total spend will run around $35 a head before drinks.
The website at oshimasiouxfalls.com is functional — menu, hours, address. The phone is (605) 338-2118. Reservations are taken for tables of four or more. Smaller parties walk in. They take credit cards, they take cash.
For takeout, call thirty minutes ahead. The kitchen handles dine-in first, which is the right priority but does mean the to-go orders during the dinner rush get longer. If you're picking up after work, calling at 4:45 for a 5:30 pickup gives them enough time to land it on the bar without rushing.
For groups, parties over six need a phone reservation a day ahead. The room can flex to a long table along the wall, but they need notice to set it up.
This is the cult classic of downtown Sioux Falls sushi. The 1,081 reviews are the receipts. If you've never been, go. If you haven't been recently, go again. And if a friend ever asks "where do you go for sushi" and you say "Oshima" — that's the right answer. You don't need to add anything to it.