Work in the mustard is a have their own firm on the surface of the detective, but in fact he is an able to summon and made a pact with the devil and the devil "devil detective.". Entrust him through the summon different devil and detective agency. And he called the devil basically is an idiot, if only sexual harassment, but super cheap, Cher, like to eat excrement Beixibu, or determination and mustard side married but very jealous of Wen Dini. Of course, also not as an aide to the half time, Wei Ling child college students. Through how they handle the commissioned, we could feel their funny to.

作品里的芥边是一位表面上有自己事务所的侦探，但实质上他是一位能够召唤并与悪魔立下契约的悪魔使「悪魔侦探」。他透过召唤不同的悪魔而处理侦探事务所的委托。而他所召唤的悪魔基本上都是一个个的笨蛋，如只懂性骚扰但又超贱的阿萨谢尔、喜欢吃排泄物的贝西卜，或决心与芥边结婚但又嫉妒心很重的温蒂妮。当然，还少不了作为助手的半工读生佐隈玲子女大学生。透过他们如何处理委托，大家便可体会到他们的搞笑才能了。