Sonoko Nanakura is a straight A student, daughter of a doctor. She meets Wataru Okochi, a tall orphan guy working in a factory, who attends school at night. Her parents warn her not to get involved, and a smart boy Yusuke Hasebe also seems interested in her.

A shikakenin was an under-the-cover trade that undertook killing in Edo. Hanemon of Otowa, an agency that introduced laborers and maids, was also one of these. Katsugoro Iseya was a timber dealer who had come in as a client. His target was the constructions magistrate Hanno, and the Tatsumiya who sipped on the benefits. Hanemon who had a stong code towards killing, where he would only kill those who do no good to be in the world, accepts this request. Baian Fujieda, a needle doctor would carry out the killing. However, the professional killer Baian fails to bring down Tatsumiya. Hanemon then looks to another shikakenin, the ronin Sanai Nishimura for the role. Although Sanai's ability with the sword is good, he lives poorly in a tenement, and accepts this commission on the condition that it is kept a secret from his wife and child. Here, they close in on Hanno and Tatsumiya again...

《雾的山庄》是古谷一行版金田一耕助系列剧的第四部，由著名女演员冈田茉莉子担任女主角，讲述金田一耕助来到旧日的大明星红叶照子的别墅里，解决二十年前一桩杀人案的故事。