...I tend not to do it as much as I should because I feel that as a foreigner I may be seen as a gaijin ahole telling the Jfolk how they should behave. Plus my Japanese isn't really up to
"Hey...mother and sproglets, I know you've had a hard day shopping but how about getting off the special seats for the 89 year old dude over there?"
At home it would be about 1 word and then a time of compliance of about 7 seconds and then the old dude would have a seat whether or not he wanted it.
Because..ya know? You should stand up for the aged.
So, what would be the best way to go about that?