Angelic Layer plans: Quick note about Misaki's Angel, Hikaru (from the Clamp Wikia page):

[In the manga, Misaki] names the angel Hikaru, after Hikaru Shidō from Clamp's Magic Knight Rayearth (a manga in Angelic Layer's world), which she was reading on the train to Tokyo, because she wants the angel to be "a short girl, but strong and happy" like Hikaru and herself. In the anime, Misaki names her Hikaru after her favorite doll from her childhood.
If you're wondering what Hikaru Shidou is like, take a look here.