Yeah! They have volleyball clubs in high schools, I'm pretty sure..! [ 'Pretty' sure since it's not like Madoka herself has been able to go to a high school yet.. or ever will.. She's just an eternal middle schooler now.

Also, part of the problem here is that Madoka is definitely not thinking of this game in terms of 'catching people'. She's so bad at this. Thankfully Ken seems to realise that it's just for fun too. ]

I bet at least one person on the train has played it!

[ Maybe they even have volleyballs in the sports car and so people played it on the train, who knows! Madoka wouldn't be surprised, considering the sheer amount of balls there.. ]