@Seran61: To a degree, yes. The last story arc/snippet/whatever you want to call it of the film is an original one that isn't in the manga at all. There's also a post credits scene that I won't spoil that is referenced in S2OVA7.
I'm not sure where you hang your hat, but Sentai FIlmworks...
Wait: Eiryou's student council was operating with no apparent oversight? Wow.
Although, if I'm being honest, Yokoshima barely qualifies as oversight for Ousai...