Genki Bakuhatsu Ganbaruger

Three boys, Kotarou, Rikiya and Yousuke were living normal lives in Blue Sky City. One day, Kotarou along with his father Toubei accidentally broke the seal that links the Demon World from the Human World. Until Eldran, the spirit of light in the Demon World appeared in front of Kotarou, Rikiya and Yousuke along with three strange machines. They were appointed to save the world from destruction as the Ganbaruger Team and use the robot Ganbaruger. After their first victory againts the demons, Yaminorius put a curse on Kotarou's dad, turning him into a dog. He did the same to the three boys but it didn't work. Except if Kotarou, Rikiya and Yousuke revealed their identities, they will turn into dogs. Now, the three of them needs to save the world from the Demon Empire at the same time, keeping their identities as the Ganbaruger Team low.