If you ever find yourself in Osaka, I'd recommend Nishiya for tempura udon soup. The tempura batter was light, and crunchy. The noodles were soft, but with just enough bite. The slurping sounds made by my surrounding Japanese dining companions kinda certified this was the place to be. Near Shinsaibashi subway. If you can't find it, have a nice young Japanese man handing out pamphlets take his time to walk you down the street, and around the corner to the door.