• I want to know the hidden spots not in a travel guide book!
• I want to Sumo,

I'd like to see some really unique places, discover tradition and customs. Is Mt. Fuji worth going there? How about Fuji Five Lakes? Is there possibility to see Sumo or Robots' fight?

About sumo tournament, it depends on your schedule. There is only a few chance to see Sumo tournament in Tokyo. Check out here:
http://www.sumo.or.jp/eng/index.html

Mt. Fuji. is very crowded! I recommend hot springs and FujiQ Highland near Fuji-five-lakes.
http://www.fujiq.jp/en/