User blog comment:RisaPlayer88/If you love blood then come here!/@comment-69.171.187.12-20140106221306/@comment-7418318-20140106225053

The regular anime episodes were made to be aired in the afternoon program and thus required a lower age-rating than the manga has.

The OVAs and movie were never aired on regular TV (or at least not in the same timeslot) and thus weren't subject to the same restrictions, thus they could go further with them than they were allowed to go with the regular episodes both in sexual content and graphic violence.

But there's a small hope that the re-launch of the anime in April might move to a later timeslot and thus is allowed to leave the censoring out... though right now that's just whishful thinking on my (and many other people's) part, since official sources didn't even hint in that direction yet.