In my mind

Josh is fifteen years old. He's just regular boy, average grades at school, not really the sporty kind of guy and he loves to draw. He seems confident at school, but that's only because of Cas. Cas helps. She's always around him, literally always. At school, at home, basically everywhere. He can't imagine his life without her. Cas knows everything about him and he knows her as well. Or does he? She's the only one he can trust.
Yet no one notices her... ever.