"Other fun stuff", eh?
Still, interestingly, a ton of people noticed what they were doing, but of course had the courtesy not to interrupt them...They just either stared or walked away...Or began fapping.
...That ending though. So it's like a car sex show now, eh? They gather to see some free car sex.
Well THAT gave a whole new meaning to the term: "Moving Violation". Also, while it's all consensual between Shigeru and Sanae, plus the *cough-cough* "onlookers" at the end were deliberately invited, perhaps there should be a note somewhere cautioning people as to whether they want to do this for real.