Power Stone of Mystery

Edward Falcon receives a gift from his father: a mysterious stone. People are all interested in it, including some pirates! They chase Falcon across the city, and he also runs into a swordsman named Ryoma, who apparently has some knowledge of it. Surrounded, the stone causes Falcon to transform into a super-powered, robot fighter, who defeats the pirates easily. Meanwhile, we see that some ninjas have been watching what Falcon's just done.