A bad cop is engaged in a violent chase to catch a yakuza boss. In his absence his wife runs away with another man, who turns out to be the very same man that her husband is hunting. Once he discovers this, he loses his nerve and turns in his badge. But the chase turns into a personal vendetta where the ex-cop plans to wipe out the entire gang.
The plot is based on the novel "Akechi Samanosuke no Koi," the final work in a trilogy by Hiroshi Kato about the forced suicide of Oda Nobunaga at the temple Honnoji. Historically, the general Akechi Mitsuhide is credited with causing Nobunaga's downfall. Kato's novel focuses on Mitsuhide's nephew Samanosuke, who fought alongside his uncle during the assault on Honnoji.
The head of Oshu, Harumichi Honma, was ordered by the boat bugyo (Commissioner of the board) Tajima Kuze to extract five gold coins to the Shogun family in Edo, and put it into Ryujin Maru. However, Tajima, who was the chief retainer of the shogunate, said that he was a member of the board, tetsugoro Funabashi, kumiyumi no Kami ichibei, and his son, masakichi, and others, and in the middle of the night, he killed all the members with poison in the night of the storm, threw Masayoshi, who was a fellow of the city, and masakichi, who escaped from the death of poison, into the sea and sank the boat to eliminate evidence.
A bad day gets worse for young detective Murakami when a pickpocket steals his gun on a hot, crowded bus. Desperate to right the wrong, he goes undercover, scavenging Tokyo’s sweltering streets for the stray dog whose desperation has led him to a life of crime. With each step, cop and criminal’s lives become more intertwined and the investigation becomes an examination of Murakami’s own dark side.
Doctor Sanada treats gangster Matsunaga after he is wounded in a gunfight, and discovers that he is suffering from tuberculosis. Sanada tries to convince Matsunaga to stay for treatment, which would drastically change his lifestyle. They form an uneasy friendship until Matsunaga's old boss Okada returns from prison.