To protect ordinary Salaryman Tsukasa Atsumi from youkai, Shizuri Ideura, a genius kunoichi, entered into a master-servant contract with him on the condition of becoming his housemate.
Contrary to her dashing appearance as she slays demons, Shizuri is actually an otaku NEET who spends all her time playing games.
As Shizuri is pampered by Tsukasa and lives a lazy life with him, a group of eccentric kunoichi gather around her...