That's not a real sex-ed class, it's an actual porno featuring something like 500 (paid) amateurs, many of who are not really amateurs I believe (or so I've...heard) BTW, those of you tempted to google your way to Japanese pron, be very careful as there are things ou thtere you just don't need to see.
It wouldn't surprise me if you were right, but it also wouldn't surprise me if it was on the level. "So you've heard?" (picture me with a big grin!) I certainly didn't search for it... I "heard" about it, as well. And no, I certainly won't provide a link for anyone interested. You'll have to do your own research.