An old manga series made by CLAMP, the creators of the "Cardcaptor Sakura". You can still find and read it online. It seems to feature cute little angels who can transform into adult forms. I am not too sure on the details, but many of the CLAMP fans expected this series to become animated in the past. However, all it got was an animated op. It's quite a shame, huh...
You can read the manga here if you wish:
http://mangafox.me/manga/wish/