With no set goal today, I just started wandering the neighborhoods in the area of my hotel.
Japan's zoning laws <a href="http://urbankchoze.blogspot.jp/2014/04/japanese-zoning.html">are pretty cool</a>. Explained very basic: they can only zone upwards and "higher" zones will always include all zones below. E.g. Low density > High Density > Commercial > Industrial. Basically the thing zoned is nuisance level. This makes for very interesting neighborhoods.
As space is scarce in Tokyo, every nook and cranny is used for something. For example the two shops under the train tracks.
Just a stone's throw away from one of the highest structures in the world (The Tokyo SKYTREE) lies a calm residential neighborhood. You can see the SKYTREE structure in the background.
It's customary for new residents of a building to tear it down and replace it with their own (new) built home. This makes for a great mix of building ages.
Over time the number of passengers increased and the trains became longer and longer. Now they almost don't fit the station building anymore.