This mansion has been abandoned for several years. Whenever I walk by it I always feel a sense of waste. I don't know the circumstances behind the abandoning, be it foreclosure, death, etc., but sitting empty for two years in a nice neighborhood is strange.
Anyway, there it is, in Tokyo, one of the most expensive cities on Earth, sitting empty, decaying, waiting to be eventually torn down and replaced with a new home. That is the process in this area. Everything is torn down and replaced with new, single family homes. Rinse & repeat.