Yondemasu yo, Azazel-san.
Genres: Comedy, Supernatural
Type: OVA, Episodes: 4
Aired: Feb 23, 2010 to Jun 23, 2014
Studio: Production I.G
Source: Manga
Rating: R+ - Mild Nudity
Synopsis:
The great detective Akutabe has an assistant, Rinko Sakuma, who is trying to learn to summon demons. This is the story of her misadventure when she actually manages to summon 2 demons unexpectedly. 

(Source: ANN)