Osaka is Japan's version of Los Angeles, as Tokyo is to New York City. It's slightly grungier, but the people are much more playful and down-to-earth than what you'll encounter in Tokyo. If you're in the Kansai / Osaka region, I'm sure you'll go to the Dotonbori area (insert famous Glico sign), off the Shinsaibashi / Namba station. However, don't forget to go to Osaka station a few stops away, where it becomes a bit more metropolitan in feel, and reminds you of Tokyo in many ways.
Don't miss out on these spots:
1. Yodobashi Camera
This is a electronics / gadget / hobbyist's dream store. There are floors of your favorite Japanese toys, manga, anime, video games, televisions, cameras, appliances-- to even watches, luxury goods, and even clothing/food as you get towards the top floors.
2. Grand Front Osaka
This is a half office building / half shopping mall, but not your traditional mall that you'd find over in the states. It has both big label and boutique-style brands, and plenty of small shops where your time will get sucked away.
3. Lucua / Lucua 1100
Another shopping mall (two sides), even more casual than Grand Front (and honestly, our favorite of the two). Lucua 1100 used to be Mitsukoshi Isetan (a department store from Tokyo), but they quickly learned that Kansai people are fiercely loyal to local brands-- hence the name / concept change.