UFO Princess Valkyrie is a Japanese anime and manga franchise centered on Valkyrie, a princess from the planet Valhalla who comes to Earth and becomes involved in a comedic harem-style story with supernatural and science-fiction elements. The series blends romance, slapstick comedy, and light fantasy as Valkyrie interacts with humans and other princesses. It is best known for its playful tone and multiple sequel/spin-off adaptations under the same main title.