While Hong Kong's density is a sort of jostling crowdedness, Tokyo's density is a sort of concentration of maximum content into the smallest possible space. This applies particularly to people and information;
view of Shibuya district
destination guides at a station
map of Tokyo's railway lines and their stations
Dense travel structure even. Unbelievable amount of stations in Tokyo, tightly packed destinations.
What effect does this concentration of content have on people? Perhaps sets up an expectation and reliance on it but also necessitates a relief from it? Japan is the home to Zen after all...