Based on the masterpiece "Samurai Detective Onihei" by renowned historical novelist Shotaro Ikenami, the series stars Koshiro Matsumoto as Agent Heizou Hasegawa.
A tale of friendship, betrayal, and forbidden love—set against the backdrop of Edo’s criminal underworld. While patrolling the Honjo district, the legendary samurai detective Heizo Hasegawa crosses paths with his old dojo friend, Samanosuke Kishii, and a local ruffian, Hikoju of Sagami. When they discover that Ofusa, the woman they both once loved, has been forced into marriage with a corrupt lord, their reunion takes a dark turn. As secrets from their past resurface, a deeper conspiracy tied to their former mentor begins to unravel—one that will test Heizo’s loyalty, honor, and sense of justice.
When he was young, Hasegawa Hirakawa was taken care of by the daughter of an izakaya, who wanted to become a secret agent. Although Hirakawa gave up this wish, Asami began to explore independently for the thief, Kogawara, the murderer, and the net cutter, who Hirakawa was looking for. Although he successfully entered the group of the uncle of the murderer, he fell into a desperate crisis.
Juzo Ono, a subordinate of Matsumoto Heizo. (yakunin government official) Ono Juzo finds himself torn between 'emotion' and 'duty' after encountering a certain woman. While Heizo worries about Juzo, he also delves into the heart of the matter. What choices will Juzo make, and what feelings will Heizo harbor for his future? Taking on the role of Juzo Ono, who holds the key to the story, is Tokio Emoto, following his performances in 'Lawless Love' and 'Blood for Blood.' This portrayal adds another layer to the character previously played by Tokio Emoto's father, Akira.
The story follows detective Heizo, played by Koshiro Matsumoto, who investigates Tanbei Chigashira, a notorious thief. Kumehachi, a former member of Tanbei's gang, claims that their former leader is an impostor. The real Tanbei Chigashira followed three strict rules: do not kill, do not rape women, and do not steal from the poor.
Master thief Kinosuke arrives in Edo to pull off one final heist for a tea-server who resembles his long-lost love, while Hasegawa Heizo’s spy Kumehachi tries to stop him, only to be exposed and trapped alongside the thief by Kinosuke's own crew.
A mysterious assassin cloaked in a haunting, seductive fragrance sets his sights on Heizo Hasegawa. Hanjiro Kaneko, a master swordsman, attacks with deadly precision, leaving Heizo to uncover the truth behind the strange scent of "White Plum Allure." As Heizo digs deeper, he discovers a tangled web of deception involving Hiko-no-Ichi, a blind decoy working for the notorious bandit leader Heijuro the Snake.
