Wikipedia
Gravion
is an anime television series produced by Gonzo. It aired in Japan from October 7, 2002 to December 16, 2002 and ran for 13 episodes. In 2004, was released and aired from January 8 to March 25 in Japan, running for twelve additional episodes, answering the questions generated from the first series.
Both Gravion and Gravion Zwei were created and directed by Masami Ōbari with mecha designs from Kunio Okawara. Both series were released in the United States by ADV Films.