The original story is published in 1970 and adapted into TV drama series in 1974 staring Hideki TAKAHASHI.
This is a side story of "Forty-seven leaderless samurai", known as the Akō vendetta (赤穂事件) in Genroku Era.
Jubei TSUKIMORI (fictional character), the secret agent and descendant of Yagyu Ninja family, decided to correct the wrong judgment by Tokugawa Shogunate in the Ako case.

The feature of this work is that there are episodes on vassals of the Asano and on Kira family's private life.

The revenge of the forty-seven Ronin (leaderless samurai), the Akō incident (赤穂事件) or Chushingura (忠臣蔵), is an 18th-century historical event in Japan in which a band of Ronin avenged the death of their master, lord Asano.
The incident has since become legendary and has been adapted into Kabuki theater in Edo period, and afterwards into novels, films, TV dramas and mangas.

公儀の歪みを正す剣豪の活躍を描く忠臣蔵外伝である。
将軍の側近・中根正冬の部下である月森十兵衛（公儀隠密）が、赤穂事件での将軍の裁きを裏で正そうとするストーリー。
本作品では、主人公の月森の活躍のほか、浅野家の家臣たち、吉良一族の私生活にもスポットをあてた。
1974年に高橋英樹を主演にしてドラマ化された。