Fujieda Baian is admired during the day as a skilled acupuncturist. However, at night, he is a highly skilled assassin, taking on contracts to quietly eliminate those whose existence is deemed toxic to society. Baian's latest target, assigned by his boss Otowa, is Shirakoya Kikuemon, the head of a powerful organization in Osaka.

In the past, Baian had been indebted to Shirakoya, but due to a conflict involving the swordsman Kosugi Jūgorō, their relationship has turned adversarial. After his lover is abducted, Shirakoya storms into Edo. With his life now targeted, Baian resolves to confront Shirakoya in a desperate final showdown.

梅安が音羽の元締から依頼された仕掛けの相手は、大阪の大元締・白子屋菊右衛門だった。以前、藤枝梅安は白子屋の世話になっていたが、剣客・小杉十五郎の件で対立する間柄に変わっていた。愛人をかどわかされ、江戸まで乗り込んでくる白子屋。命を付け狙われた梅安は、対決する覚悟を決め、白子屋に捨て身で立ち向かっていく…。