My sister worked at Kumon for a while.
For those folks here who don't know, they're a Japanese juku (cram school) which expanded to America mostly to service the children of Japanese parents abroad. (A common fear is that a student who spends a few years in an American public school prior to returning to Japan will be academically crippled.)
I have only two things to say about mathematics education in Japan: it works very well for students in the academic track, and it isn't considered strange to have girls say they like it. So the next time you hear someone saying how we need to address gender balance, there is your answer: soul crushing drills!