Based on a Japanese science fiction manga series written and illustrated by Keiko Takemiya. It was originally serialized in Asahi Sonorama's Gekkan Manga Shounen magazine, between January 1977 and May 1980.
In 1978, the manga won the first Seiun Award for manga, and in 1980 also won the Shogakukan Manga Award for Shounen/Shoujo manga (along with Takemiya's Kaze to Ki no Uta).