It's got something for everyone!
Is it a bill by-the-yukkuri or by-the-hour sort of thing?
Or is it like a driving range and they just give you a bucket of the things up front at the register?
I say bucket because that's ideal for both the customer and the cafe.
For bill by yukkuri it is cheaper just to pick a random stray in an ally.
For by an hour...some people can probably kick the shit out of a LOT of yukkuri in that short time frame.
Buckets is the best simply because both you and the cafe know how much you get for what you pay
Speaking of driving range, I'd imagine they'd have some amazing machinery on hand for use by customers.
It reminds me about a Japanese restaurant (I think), where you can pay to write something you are angry at on a dish and then you break it.