Sho Kosugi stars (as well as produced) this picturesque and exciting swashbuckler, directed by Gordon Hessler. Kosugi plays Mayeda, a 17th-century Japanese samurai whose clan, headed by Lord Ieyasu (Toshiro Mifune), is waging a bloody battle with a rival clan. The rival clan has the advantage of using punk-burning muskets, which work fine unless it rains, rendering the firearms useless. Ieyasu sends Mayeda to Spain to one-up the rival clan by arranging the purchase of flintlock rifles, which are immune to rain. Mayeda is accompanied on his journey by Ieyasu's young heir Yorimune (Kane Kosugi), along with a traitor -- the clan's Catholic spiritual advisory Father Vasco (Norman Lloyd), who has made a deal with the rival clan to kill Mayeda and Yorimune and to make sure that the flintlock rifles never reach their destination. However, the plot fails. In the process, the gold to pay for the rifles falls overboard, and Mayeda arrives in Spain penniless at the court of King Philip (Christopher Lee). King Philip refuses to give Mayeda the rifles, until Mayeda saves his life during an attack of rebels. But even though Mayeda now has the king on his side, he has earned the wrath of his advisor Don Pedro (David Essex) by falling in love with his fiancee Cecilia (Polly Walker). Mayeda and Don Pedro eventually tangle in mortal combat.
~ Paul Brenner, All Movie Guide