Two mysterious tough guys, Ryuji Hoshikawa and Kyotaro Ochiai, win money at the track but have some of their winnings swindled by Tetsu, a member of the Hyakkikai posing as a car dealer. Mr. Makimura, an elderly fish seller, cannot pay off his debts to the Hyakkikai so he jumps in front of a car being driven by Ryuji and Kyotaro but they stop in time and help him by robbing a Hyakkikai gambling den and giving him most of the money in order to repay his debt. From wikipedia

One day, Takechiyo, the eldest son and heir to the third shogun, Iemitsu, was attacked by a group of Negoro ninjas. Why would the Shogun's own secret service target the heir to the Shogun's throne? Seven samurai, including Ishikawa Gyobu, a powerful swordsman who is Takechiyo's personal guard, confront the band of assassins, each using his own special skills. The clash between the seven samurai and the band of assassins grows more intense with each battle......