Some commercials for the show in Japan featured an early version of the opening theme, "Shooting Star", playing in the background. This version of the song has never been released.
Episode 14 was not broadcast on television in Japan but was sold as a separate direct-to-video release. The episode is contained on volume 4 of Bandai's region 1 DVD series in both its original Japanese and an English-dubbed form.
The character, Koishi Herikawa's given name means "pebble" in Japanese.
Mizuho speaks about the history of her father, which begins in 2009 when he was rescued from a spacecraft that was off the track, after he met the Mizuho's Mother and she was born, she suggests having more or less 21 years, therefore, the year when all the plot happens could be 2030 or 2032.