"People in Tokyo sleep, on average, 5 hours and half at home, (and they add to that their sleep during the commuting time in a train.)"<p>That does not sound healthy at all. How does this work?
The enthusiasm for superblocks is interesting. That's been a disaster in US city planning. It's associated with housing projects. Stuyvesant Town in Manhattan, which is a huge, expensive apartment complex, gets higher rents for apartments which face the "outside" streets than for those which face the interior open space.
That Sumida River drawing is a nice touch. When I used to work in Tokyo I'd often go to the river at lunch, it's very relaxing and I love being near water.