There aren't any expensive houses for sale. A lot of the time, Japanese have to buy land and build themselves because no house is available and there isn't any inventory.

That's because the Japanese build such lousy houses, including the so-called "luxury" ones, which are designed to fall apart. Even the prime minister's former official residence became invaded by armies of rats and cockroaches and had to be abandoned.

Custom-built homes are de riguer for wealthy people here.

First-world problems

I thought Mikitani already lives in Shibuya. I've seen him a couple times, walking towards the station with his son.

Kimu-taku's house cost about the same - I've seen it and it's nothing to write home about. It's nice, of course, but not 2bn yen nice...

There isn't any inventory

Because government conspires with the construction sector to perpetuate the myth that houses should only last a few decades, and older properties are undesirable and valueless. Result: most people struggle to accumulate wealth, and Japan Inc has plenty of willing hamsters for its wheels.