UFO Princess Valkyrie
English title: UFO Ultramaiden Valkyrie
Japanese title: 円盤皇女ワるきゅーレ
Type: TV
Episodes: 12
Premiered: summer 2002
Source: Manga
Genres: Comedy, Sci-Fi, Ecchi
Studios: TNK
Producers: Media Factory, Nippon Columbia, KlockWorx, Toshiba Entertainment, Omnibus Promotion
Duration: 23 min per ep
Rating: R+ - Mild Nudity

UFO Princess Warukyure, aka UFO Princess Walkyrie is about a princess from outer space who accidentally crashes on earth, where Kazuto desperately tries to maintain the public bath of his grandfather. Due to circumstances, Kazuto receives part of princess Walkyrie's soul which forces her to stay there with him. But that's not the only problem ... because her soul lost strength, the princess transforms both mentally and physically into a little kid!

(Source: AniDB)