This was a really nice series, I watched the OVA and it was really good too.
Tho I still wish it wasn't just OVA but a 12 episode series. (cause apparently a certain site review gave the series a low rating and bad review... so they decide to go with OVA instead of TV)
Either way, I think this is the final OtoBoku series, don't think there any other being made into Manga or Anime. (cause of low rating)
Cause far as I know... there isn't any more Game or Novel being worked for OtoBoku (for 8+ years now), which is where the manga and anime comes from.