I am not really sure why exactly but that is very, hot. I Love the way she stops in mid sentence, turns, and takes the 'load'. Also love the way the camera man comes running about half way through to drop his load on her.
Japanese censors are really wierd. I remember seeing a clip (probably here on TERB) where a young woman had a funnel up her butt, while another woman put baby eels up there where the sun don't shine. She then shot them out of her asshole. The strange thing was that her pussy was pixilated.
It seems to be okay to show baby eels being put up the asshole...but don't show that pussy!!!