To be clear it is the Glico sign (if you are searching for it) in the Namba/Shinsaibashi area of minami (south) Osaka. If you only have one day, this is a good district to shop, explore and eat in. The walking bridge the sign can be seen from is full of people and the exterior of the club that Michael Douglas enters in "Black Rain" was filmed at the north end of the short bridge, although it has since been torn down (a real shame).
Ame-mura might be an interesting cultural walk on the other side of Midosuji (the major North-South street through Osaka) if you want to see young, alternative culture. Great vintage stores, toy stores, music shops, and clothes clothes clothes.
Tell me what are you hoping to find in Osaka, and I can give more detailed advice. I lived in the area for a few years.
