THIS OVA INCLUDES GAY SEX, RAPE, NUDITY AND BLOOD - if want to avoid those, don't watch it. The anime doesn't have these, so you can just watch the anime without watching the OVA. This OVA shows what would happen to Aoba if things had gone wrong on episode 11 of the anime. It has good quality animation because it came on DVD and there isn't much of a plot to insert here. The voice acting is really good on it and it's a great adaptation of the bad ends. Excluding how short each part was (but I understand why it is like that), I haveno complaints.
So, nothing I wrote on the first sentence bothers you - go watch it.