Late at night, a mysterious spaceship landed on a lake surrounded by a tranquil forest. The group that emerged from the vessel kidnapped Professor Katou, the head of space engineering, along with his family. The Professor's second son, Yuuji, an American football player who had run away from home, was in the middle of a game and knew nothing of what had happened. The four young people watching him were Mark, Dickey, Franco, and Yuri. They were a team of four psychics who had been training in a secret base. Having witnessed the previous night's events, they believed them to be an alien attack. Convinced that their only option was the transforming robot Baratack, they used their psychic powers to kidnap Yuuji. Baratack could only move by combining the powers of Yuuji and the other four acting as one. When all five, including the astonished Yuuji, cried "Pentagoras Unite!” Baratack emerged. Yuuji was overcome with violent rage, his fighting spirit burning to defeat the Golteus reptile army.