Dobu (Kunie Tanaka) used to be a soldier but now is a private detective. Three vagrants were killed in a shrine, and Dobu found out that those three had a grudge on a timber whole seller, Hinokiya. He reunited with Zirokichi (Takeo Chii), one of his friends and Nezumi Kozo (a thief) , and he infiltrates Hinokiya together.

Dobu, an Edo samurai, is tasked with investigating a string of noble murders in Kyoto, disrupting his routine in Shimotani.

After six exiles return to Edo, four are mysteriously killed. Two survivors, Kosuke and Kingo, lead a search to uncover a hidden motive behind the murders.

In Edo's autumn, a wave of murders hits, targeting those linked to an old case. A young man, Utaro, takes charge, but Dobu's love interest is involved.

After two thugs are killed, Dobu and his crew have three days to catch the murderers. Dobu suspects a hidden mastermind influencing the magistrate.

A spree of murders in the city targets peddlers and komuso monks, all killed in the same method. Dobu investigates after a ronin's death with a unique clue.