This movie was released in 1981 in Japan. After the pilot was a no go, Tezuka and Sanrio teamed up to create the first movie. Similar to the pilot, this movie was based off a few chapters of the manga. Obviously a few things were changed for the movie version, but a few of the characters were included. One of the most loved parts of this movie is the music which many people are able to remember even after many years.
The beginning of the movie shows a backstory for Unico. Instead of Venus being the one trying to be rid of Unico, there were simply many gods that wished for Unico to be gone. Nishi Kaze drops Unico off on a deserted dark island which also happens to be the same place Unico was dropped off at in the pilot episode. Unico meets Akuma-kun and Chao as the movie goes on. Ghost Danshaku appears while Chao is in human form and wishes for her to join him at his castle. Unico soon realizes that Ghost Danshaku wants to kill Chao and he goes off to rescue her.
In the manga, Ghost Danshaku is not Satan. He is simply a very evil man who enjoys killing animals and hates cats the most. In the movie he seems to be extremly evil rather than just a snobby pretty boy who enjoys killing.