It is the year of 2401, three teenagers Dilu, Yaoyao and Xiao'An are going for an outing. During the outing, they found a mystery object, the Galaxy Star, which comes from the very core of the Galaxy. The Galaxy Star contains a secret. Dilu is so curious that he wants to unveil the ultimate secret, so he encourages Yaoyao and Xiao'An to set foot on the journey with him. With the help of the spaceship pilot Lily and the GALAXIA, they start to explore the solar system and unveil the ultimate secret of the Galaxy Star.