This OAV series was a complete letdown for anyone who saw the TV series. Anyone who didn't see the TV series wouldn't be able to begin to comprehend if this was all they saw.
The story was extremely rushed here, as it covered a large portion of the manga in a very short time (a mere 3 episodes). This was in no way acceptable to do this with. In my humble opinion, another TV series was needed.
To the TV writers defence, however, there were some things deleted from the TV series that were existent to the manga that did not make the premise so absurd. However, it was still really bad.