Every Day by David Levithan
Waking in a different body each morning, A resolves never to get attached to anyone. When A falls in love with the girlfriend of someone being inhabited, however, the context of A's life and world becomes blurred.
Review from School Library Journal Starred:
Levithan uses a straightforward hook-a 16-year-old soul named A wakes up in a different teenage body everyday-to explore identity. While the mechanics of A's ability are intermittently examined, they quickly become the backdrop to the myriad lives A inhabits and the strong identity he (or she as A does not identify with either gender) has created to survive this transient existence. His strong moral code is based on respect for the person whose life he disrupts and the consequences he doesn't have to face. That code is challenged when he falls in love with a girl named Rhiannon after spending a day in the body of her slacker boyfriend, Justin. Complexities arise when one of A's subsequent hosts, Nathan, has an awareness that he was possessed (presumably by the devil), and the story goes viral. Navigating a new body daily while attempting to build a relationship with Rhiannon and make sense of his condition leads to many philosophical quandaries that Levithan infuses with intelligence and poignancy while remaining nondidactic. Indeed, every step of the narrative feels real and will elicit a strong emotional response from readers and offer them plenty of fodder for speculation, especially regarding the nature of love.