The two-sides of Tokyo
Asakusa is a great part of Tokyo, if you're a bit overwhelmed by excessive lights and skyscrapers. It's very touristy though so be aware there's going to be tourists everywhere during the day. If you can spend some time in both the Asakusa area and Shinjuku area, i would highly recommend it. You can see the best of both worlds.
Insider Tip:Harajuku shopping in cat street! Vintage shops for miles, they're amazing quality and so extensive for a great price.