It has been well documented that Tokyo tends to build a lot of housing. And the argument goes that this has helped to maintain a certain level of housing affordability. The city is constantly building and rebuilding. It also has different views about housing. Now, we could, of course, debate how much of its relative affordability is a direct result of supply but, regardless, there seems to be a lot of it. In 2014, the city of Tokyo saw 142,417 housing starts, according to this recent FT article. This is compared to ~5,000 units across the Bay Area (2015 data), 83,657 units for the state of California, and 137,010 units for all of England.
If you’re wondering how Toronto is doing, here are the latest numbers: