[taeric]

The first one could explain why it isn't spreading there. Without testing, hard to know if that is accurate. Reports from other threads supports that it is there, but not severe cases. (Sadly, anecdotes...)

Second is also tougher to square. The risk pool is supposedly older people, per reports from Italy. But, that doesn't seem to square with age profiles of Japanese. So??

[brigandish]

One difference could be that old people in Japan are all too often living a solitary existence or not in frequent touch with their family. My wife brought this up last night as I was discussing this thread with her and out of everything I've seen, read, and considered, this seems to be the one thing that could stop it - they were already socially distancing the most vulnerable group.

Still, there's a long way to go for this thing.