This is a project I did while studying in Japan. The Animation is called "Memai no Kokoro" which means "Vertigo Heart".
It is about a world, where the sky is below and earth is above. Nobody knows what is down there beyond the sky. There is only one way down, a tunnel leading through the sky. But it is very dangerous and nobody ever came back. In this scenario the adventure of "Avedine", a young girl who wants to become an engineer, and her friends starts. This animation is the introduction to the world and shows the events that led to the start of the adventure.
If you want to see the movie with english or german subtitles, please check it out on youtube.