Castiel Moves In

Castiel gets angry when he discovers Sam and Dean have a sister, Sara Winchester, who's been looking after orphaned monster kids left without family after the brothers finish cases. So Sam, Dean, Sara and even Balthazar give him a challenge. If he can live with Sara and the kids for a full month, and still find the kids evil, he can do as he sees fit. But will Cas be able to cope with seven excitable children, when he's barely able to understand adults?!