On their way to maneuvers a group of Japanese soldiers get transported four hundred years back in time to the warring era with a tank, a patrol boat, a helicopter and a jeep equipped with a machine gun. They are trying to figure out how they got where they are when they are suddenly attacked by samurais. Lieutenant Iba (Sonny Chiba) and his men end up in the middle of a battle and the circumstances find them joining sides with Kagetora, the war lord of lord Koizumi and his men.
The battle rages on and the modern soldiers are stunned, shocked and amused by the fighting around them. Two of the soldiers died, and some of the others begin to get discouraged about getting back to the present.
Meanwhile Iba gets invited to the castle but he doesn't want to take sides. Kagetora kills the messenger and sends a message back to the castle, turning his back on his lord. He asks Iba to fight with him, and they can rule together. Iba tells his men that if they fight they will throw history out of order and be returned to their time by the god of time.
One of the soldiers meets a girl and they fall in love. Samurais attack some of the soldiers again and its swords against guns.
Some of the soldiers, led by Yano, take the boat and go out on their own as pirates. They pillage and take the women. Iba tells him to come back in but Yano just ignores him. Iba in his helicopter find Yano in his boat. Yano lets all the women go. The boat then fires on the helicopter and eventually they blow the boat up.
Iba and his remaining soldiers decide to join Kagetora in his fight against Takeda Shingen. Kagetora takes a meeting with Lord Yukinaga and then assassinates him. Iba and his helicopter then pulls him up and helps him escape.
The battle then rages on with Iba and his men fighting Shigen's men. In spite of their modern weapons Iba and his men have trouble with Shingen's men and lose most of their equipment. Iba finally fights his way through and confronts Lord Shingen. Dhjgen calls his men off and fights Iba man to man. When Shingen cuts through Iba's sword he pulls out his pistol and shoots him and then Iba takes his head.
Iba and his remaining five men go to join Kagetora to rule the country. The Shogun yhen pressures Kagetora to get rid of Iba. he tells him that if he sides with Iba he must die too. Kagetora brings some men to finish Iba and his men off. As Iba approaches with a sword, Kagetora shoots him with a rifle. Then all of Iba's men are finished off by archers, except one.
The movie has a spaghetti Western kind of tone to it. On the surface it seems to take itself seriously but underneath it is all farce. The only thing that I didn't like about the movie was that it was just too long. The story just wasn't good enough to justify it's length. There is an 85 minute version out there, and it might be better. It didn't all work for me, but i still think it was pretty good.