Reideen

Saiga's life as a high school student with a talent for mathematics is turned upside down when his family receives news about his father, a renowned archeologist who vanished years ago. His remains are found near Japan's pyramid, a site suspected to be man-made, along with notes and artifacts that need to be identified. A meteor crash-lands, releasing a robotic lifeform that wreaks havoc, and Saiga's dad's research activates a mysterious bracelet that merges him with an ancient robot, Reideen, buried within the pyramid. Now, Saiga and Reideen must defend against the alien threat from the meteor.