必殺スペシャル・新春決定版！大奥、春日局の秘密 主水、露天風呂で初仕事/1989/Dexter TV special O-oku, Kasugano-Tubone’s secret
Edo Castle. The Shogun had his own halem（O-oku） for his successor, with one wife and many concubines, and had 55 children. As a result, the Shogun was about to have a problem with his successor.
With the coming of the New Year, the shogun’s representative, Kasugano-Tsubone, an elderly lady in the halem, was ordered to go to Zojoji Temple to pray for good health and protection from evil spirits in the halem.
On the day of the visit, while praying, a strange smoke suddenly filled the area, and a group of Ninjas broke into the temple.
Mondo killed one of them, but at the moment of his death, he left a message saying that he had been betrayed by his client.
This Ninja claimed to be Mochizuki Ichigaku, a Kouga Ninja.
Can Rui, the wife of a Kouga ninja with amnesia by trauma, remember her revenge?
Kasugano asked if Mochizuki, the Kouga ninja, had said anything to him on his deathbed, but Mondo talked nothing to her.
On that day, the Kouga clan’s mansion was investigated by the town magistrate, but at the request of Mondo, Mochizuki’s wife Rui and his younger sister Rie escaped, but Rui hit her head on a stone wall and lost her memory.
Later, Mondo goes to the Shogun’s halem and is asked by Kasugano-Tsubone to investigate a disturbing situation in the inner palace concerning the succession of the heir to the throne.
Who is the mastermind behind the conspiracy?
Scenes from the New Year’s festivities in the O-OKU, including parody characters such as the robber Rat Boy（Nezumi-kozou） and Katsushika Hokusai, are also featured in the film.
Mondo, who has disappeared from the washroom, takes on the intrigue in the inner chambers of the ladies’ chambers.
cast & staff
| role | actor & actress |
| Mondo Nakamura（中村主水） | Makoto Fujita |
| Kayo（何でも屋の加代） | Izumi Ayukawa |
| Masa（鍛冶屋の政） | Hiroaki Murakami |
| Kasuga-no-Tsubone（春日野局） | Mayumi Ogawa |
| Sataro Sekiguchi（関口佐太郎） | Hiroyuki Watari |
| Ichigaku Mochizuki（望月一学） | Jimji Shimada |
| Rui Mochizuki（望月るい） | Ai Saotome |
| Rie Mochizuki（望月りえ） | Noriko Watanabe |
| Sen（せん） | Kin Sugai |
| Ritsu（りつ） | Mari Shiraki |
