Ichirin-sha

On a planet very similar to the earth... Here, the missile mechanoids started to have its own will and control, and were driving the human beings into serious danger. Shaleen was the last ICHIRIN-SHA (unicyclist) in the world, traveling the world on his beat up motor unicycle. One day, when Shaleen was running from the attacks of the missile mechanoids, he stops by a ghost town and meets a mysterious girl who was constantly targeted by the mechanoids.

Note: Originally meant to be a full length movie, the project was cancelled, but a 7 minutes long trailer was released before that.

(Source: AniDB)