Miracle Hime Jubilee

Miracle Hime Jubilee's title character, the 531st princess of the planet Keyhole, takes a joyride on a UFO. She lands on Earth, where a boy named Kiichi Masuda inadvertently pulls out the UFO's key and resets the craft — stranding Jubilee. In order to return home, Jubilee and Kiichi must recharge the key's energy in various locks on Earth.

(Source: Anime News Network)

This is the second title in Ken Akamatsu's "Illegal Out-of-Print Manga File Purification Project." Which shares out of print manga online, in a number of languages, supported by ads.