Watashi no Arika.

When surgery to remove a tumor goes wrong, Kunihiro Sakaki finds himself in what seems like a dream. A girl resembling an angel appears before him. She informs him he's on the verge of death, but he isn't bothered too much by this news. She then asks him what kind of life he'd like, to which he responds saying he'd like to be able to sleep with any woman he wants. On top of preventing his imminent death, she offers to grant him the power to make the life he desires a reality. In exchange, she wants him to allow her to live inside him. Where will Kunihiro's life go from here?