Five Element Ninjas

In ancient Hong Kong about the Yuan Dynasty, Chief Hong challenges his rival, Yuan Zeng, for the title of martial arts master. Their students face off against each other, and when his students are easily defeated, Hong calls in a samurai to fight on his behalf. Zeng's students are initially dismissive of a Japanese martial artist, but he defeats his opponent, whom he goads into committing suicide. Zeng's student Liang Zhi Sheng defeats the samurai, but before the samurai commits suicide, he warns that an allied ninja clan will seek revenge for his death. He tosses his ring at Zeng, who is poisoned when he catches it.