Henjin Tantei Em

Rudy Art, the owner of an antique furniture store, obtains the "Devil's Branch" and accidentally summons the devil. Confused, Rudy rushes to his classmate Em Kelsner's detective agency. This Em has always been a weirdo!? From that day on, Rudy gets dragged around by Em!?

Volume 1: Satanic Branch (サタニックブランチ)

Volume 2: Goblin's Rye (ゴブリンズ・ライ)

Volume 3: Lampshade (ランプシェード)

(Source: Futabasha, translated)