If you find yourself in Tokyo and wonder what you should see I recommend going to Asakusa to get a feeling of old Tokyo and past traditions. Walk through the Kaminarimon Gate (Thunder Gate) and start exploring. The original gate was built around 1000 years ago. I thought Asakusa was very beautiful and if I ever go back to Japan and Tokyo which I hope, I will visit this area again. Afterwards you can walk to Tokyo Skytree and that right there is a full day of fun in Tokyo.