Here’s a 15 minute documentary video on the uniquely Japanese 3 person mamachari bicycle. In Japanese with English subtitles.
The narrator talks about recently changed law that allows these huge bikes, describes differences between these and more traditional bikes, and follows a young mother as she takes a safety class.
Features of these bikes include heavy duty ultra-low step through frames, low center of gravity, handlebar lock, wide stands,
Via the Mama Bicycle Blog, from where you can have a 3-seat mamachari imported into the USA.