The series because it's longer has different strengths and weaknesses compared to the OVA.
The first 10+ (too many) episodes follow the formula of
1. Miyu + classmates and how their relationships begin/grow
2. Some shinma appears
3. bad things happen
4. Miyu and Larva defeat the shinma and
5. There are consequences
After a while it got really boring. The only excitement was trying to guess what form the shinma would take. There was reuse of a lot of the frames and the plot got repetitive and predictable, which made this less exciting than the OVA.
On the plus side, interweaved into the plot was the continuing story of Reiha, another shinma who has an antagonistic relationship with Miyu. In fact the character background episodes for Larva, Reiha and Miyu are easily the best episodes in the series. Notice how good I am at not really giving out any spoilers ! <(^.^)>
Tension builds up until the last 2 episodes (the climax) which are easily worth a 9 in plot/story. The ending was much better than the entire series. However, to be fair, having had to sit through 18ish repetition/boredom to watch 8-9 good episodes made me unable to rate this series any better than a 6 overall.
I really did like the haunting flute theme tho!
