Come to London and you will find 12 year olds openly vaping on the upper decks of the buses. A couple of weeks ago I saw a mother absently pass her vaping stick to her 7/8? old to have a puff whilst waiting outside a shop.
My own kid (then 13) spent a lot of time hanging around other unaccompanied teenagers in central Tokyo this summer. In England, about 10% of under 18s regularly vape and the number is climbing, it does seem higher than this in London.
Not saying that it doesn’t happen or it isn’t a problem, but Japan is definitely doing something right when it comes to reducing tobacco dependency.

ETA - Apparently the problem is not at its worst in London, there are places in England with a 30% uptake amongst young children
https://hansard.parliament.uk/common...nder-AgeVaping