Unico the unicorn is once again in a new place. During his journey with the West Wind, Unico meets Tsubasa, a talking tree boy. The Earth has become totally ruined to the extent that no creature can live there, because humans have drained it of all resources and destroyed the environment. Unico and Tsubasa go on a journey to find a way to make the Earth habitable again. They finally meet the Sphinx and the "time fairy" (Astro Boy/Atom) at the end of their hard journey. They decide to go back to the past and prevent humans from taking the wrong path.