Unico, a magical unicorn, is born with the ability to bring happiness to those who meet him. However, an evil demon named Kuruku wants to harness Unico's power for himself. Unico must embark on a fantastic adventure, facing various challenges and enemies, in order to defeat Kuruku and bring happiness to the world.

This is the fourth original animated piece for the Tezuka Osamu Animation theatre that takes up Tezuka Osamu's message of "Saving our Fragile Earth" as its theme, and together with Unico's adventures commemorates the theatre's first anniversary. Unico, a unicorn's child, has dropped down from heaven. During his journey on the north wind, he meets Tsubasa, a tree boy who can speak. 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 inhabitable again. They finally meet the Sphinx and the "time fairy" at the end of their hard journey. They decide to go back to the past and prevent humans from taking the wrong path. However, they can stay in the past for only five minutes. Will they be able to alter the future of the Earth in such short time? Their adventures to restore the Earth begin...

Unico, a magical unicorn with the power to bring happiness, is pursued by a black cloud determined to take away his gift. With the help of a bird named White Feather, Unico must find a way to defeat the cloud and protect his ability to spread joy.

Unico in the Island of Magic (1983) follows the journey of a young unicorn named Unico as he ventures to an island ruled by an evil magician. Unico must use his magical powers to save the island and its inhabitants from the magician's wicked spells and bring happiness back to the land. Along the way, Unico befriends a young girl and together they face various challenges and obstacles. Will Unico be able to overcome the dark forces and restore peace to the island?