We went on a ~5 hr food tour of Osaka with Minako as our guide. She picked us up at 9:30, from our hotel in Namba, and we were off to Tsuruhashi market. Bring money for an all-day subway pass, the tour guides are not allowed to buy you a ticket by Japanese law. At Tsuruhashi, we sampled some Japanese side dishes. Minako speaks very good English, and it's great having somebody who the shop owners know, and who can answer all your questions. We also got to try 3 types of tuna, including a good amount of o-toro and chu-toro. Next stop was a sake store, tried 3 types of sake. Then kushikatsu in Shinsekai. We then had a chance to stop in at a great knife store, owned by a Dane expat. This is awesome because you'll actually get great explanations of how knives are made, and you'll get to try out some blades. Having an owner that speaks English really helps. Final stop was Dotombori for okonomiyaki before being dropped off at our hotel.
This is a great introduction to Osaka, both it's culture and it's geography. If you'd like to try Japanese food, but you're not sure of what to order, having a guide is very helpful. Also, if you like to go to some local, off-the-beaten-path type places, on this tour you will.
I'd HIGHLY recommend you take this tour early during your Osaka stay.