A 3D movie about 47 samurais who, upon the death of their master, are unable to commit hara-kiri, thus they are shamed into becoming the titular ronin. Ronin is a Japanese term that means lordless samurai. Despite the great wound to their pride and spirit, the newly appointed ronin rediscover their reason to fight when they decide to avenge their dead lord. Over the course of a year, the ronin patiently wait out their plan against the villain who brought about his downfall. But what will happen when Kai (Keanu Reeves), a half-breed outsider, with a mysterious past falls in love with a princess?