On paper, this show appears to be a number of clichés of the supernatural anime subgenre. Youths going to an exorcist academy to fight demons and the drama and hijinks that occur along the way. 9/10 times I find that type of anime to be very standard and underwhelming, but this series seemed to execute those cliche's in a manner that made this series surprisingly engaging.
I have a family member who went through film school who has told me that you can have the most derived and clichéd story, but it still can be superb, it's all about the execution.
Now this series was not even close to the stand out originality of series such as Cowboy Beebop, Attack on Titan, Trigun, and such but it stands on its own because of an engaging cast of characters, especially the two main characters. The twins.
This series may not go into the depth of some of the above mentioned series but it has great themes of friendship, being an outcast, family and such.
And I'm not much of a fan of the chibi thing, and it didn't at all get on my nerves or unnecessarily break from the drama as I've found in other shonen series with chibi.
Overall, not one of the top animes out there but highly recommend watching for any anime fans out there.