While waiting at a traffic light near Setagaya Koen this morning I noticed a father and daughter on an electric assist bicycle. OK, nothing unusual about that. But in this mornings case it was the little girl, no more than 6 years old, who was doing the pedaling. Dad sat back on the seat, hands on the handle bars, legs dangling, while the daughter stood on the pedals in front of him propelling the bike forwards.
I don't have any idea how long she can keep that up, but the denki assist bike certainly must be giving a fair amount of assistance.