Manga: Ikuhara Takeya is a normal student attending a high school where his friends are obsessed over the alien creatures, DearS. The DearS are used as slaves and consider themselves nothing more. One day when Takeya is walking, he finds a DearS named Ren on the street. When Ren falls into the middle of the road, with a truck behind, Takeya pushes Ren to the sidewalk. From then on, Ren swore to become Takeya's slave, and the relationship gift soon grows between them.
Anime: Ikuhara Takeya is a high school student living a normal life. He is not interested in the commotion around a UFO filled with beautiful alien females that crashed on earth a year ago. The aliens, known as DearS, are deciding to take permanent residence on earth. What no one knows is that these aliens are a slave species whose sole purpose is to serve and please their masters. One day, Takeya spots a person shivering behind some bushes. This person, Ren, is one of the DearS, and after being saved by Takeya she chooses him as her master. Takeya, who doesn't know about the master-slave relationship of DearS, tries to learn Ren the normal lifestyle of the people on earth, though he constantly fears that Ren is an evil alien who's trying to brainwash him. But Ren isn't like other DearS. She is in fact malfunctioning and is being tracked down by their leader. Meanwhile, Takeya begins to learn more about DearS, and a mythical DearS relationship called “Gift” begin to develop between them.
(source: ANN)