Awhile back mothers were banned from riding a bicycle with two children.  This was about the same time they said you cannot hold and umbrella while riding a bicycle.  More recently the law about mothers riding with two children has changed.  They are now allowed to ride with two children if they purchase a specific type of bike.  The new bike is quite expensive, costing $600 and up.  It is supposed to be sturdier. I cannot imagine riding with two children, especially with one virtually on the handle bars.  It was a challenge riding with one child on the back and I even ended up dumping Kristina on her head when she was quite small.  That was in the pre-helmet days.  I was so grateful to get one of the first bike trailers.  And just so you know, the Japanese rarely wear helmets.    Here is a photo of a “Mama-san” bike, be sure to take note of the long black box between the seat post and the rear tire, it’s the motor: