We love markets in Asia, but unfortunately the markets in Okinawa are overall a real disappointment and cater primarily to the tourist trade.
*The arcades behind Kokusai street involve lots of cheesy souvenir and T-shirt shops. The fruit and veg is overpriced. The fish and meat market is more vibrant, but the upstairs restaurants are vaguely depressing. The redeeming feature of the market is a Okonomiyaki joint - a one-man show with a great product (light pancake, tons of cabbage, an egg, and special sauce) for only 100Y. There is also a cute coffee joint down an alleyway off the fruit/veg section - just an umbrella out front, a bar, and 4 stools.
*Nago seems as if it should have a good market, but we have gone into it on several occasions, day, night, weekend, weekday, and never seen it actually happening.
*Okinawa City's arcade between Gate 2 street and BC street is pathetic. Som Chai is the main reason to go to this area.
*The night market in Hamby town is geared towards a young nightlife crowd, with hiphop / reggae clothes and music and some snacks to go with your drinking.
*Motobu town's market does not have much going on, except a decent looking fishmonger. It is a good place to go if you want to buy the clothes favored by respectable middle aged Japanese women.
*Kin has an interesting market. You go north on the 329 of the Kin IC exit and see it on the left; on the right there is just a sidewalk and the sea. This is in part a flea market - the stuff is amusing but overpriced. There are lovely looking local veggies and a girl selling sweet potato desserts. Best of all, there are a couple stalls doing food - we ate oden at the back of the market. The accompanying noodle soup was deliciously garlicky.
*Up the coast north of Nago, there are some fruit vendors selling pineapples and other good stuff for reasonable money.
***In Nakadomari (Onna) on the 58 there is a big souvenir complex with a parking lot that is pretty busy. This place is an Okinawan emporium for the Japanese tourist and local. Inside the building, they sell local produce for lower prices than Jusco, Kanehide, and the commissary. They have lots of beautiful fruit and veg you don't see in the shops - beets, turnips, fresh greens, guavas, custard apple, etc. Outside, a series of food stalls do everything from marinated pork knuckle to fried seafood to mochi desserts. On the top floor Boulangerie de Paris does soup/salad lunches, but we did not get to sample their baguettes. The complex also has stalls selling the typical trinkets, T-shirts, brown sugar cubes, etc.