Chloe is a normal teenage girl, if there's any such thing, until a formless alien being inhabits her body. The being named Welkin has entered Chloe's body as part of a school project. Chloe agrees to let this weirdo observe her life for three days as long as Welkin doesn't interfere. Welkin tries to respect Chloe's rules, but Welkin's stream of alien commentary as Chloe deals with boys, her coach and math homework has a comic, and sometimes enlightening, impact on Chloe's life.