Yondemasuyo, Azazel-san.

Also known as:  You're Being Summoned, Azazel-san

The TV anime series Yondemasuyo, Azazel-san. is based on a supernatural gag comedy manga authored by Yasuhisa Kubo, which also received two OVA episodes created by Production I.G in 2010. The story revolves around the detective Akutabe, his assistant Rinko Sakuma, and the various magical demons that Akutaba uses for his cases - including the titular Azazel.

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Producers, official website and other details: AniDB, ANN, Wiki