I mean, they're all old enough they should have had their rags, so how the fuck can they not know?
How irresponsible is the damn teacher, geez give them the real info or they're more likely to get knocked up early, dumb arse. Or maybe abstinence only actually works in Japan cause of all the herbivores that prefer 2D?
Poor Kasumi being the only sane one in the room all the time