When the super cool Sally Anne and the ultra sassy Rita discover that their crushes, Johnny and Walter, are being transferred to an all-boy Catholic school, they devise a plan. Disguised as nuns, the two Sisters join the convent where they are selected by the health-crazed Father Berkenshire to rescue the doomed school by putting on the best Christmas spectacular ever. But when Sally Anne discovers that Johnny is in love with a shy boy named Trevor and Rita discovers that Walter has an unhealthy obsession with Father Berkenshire, the heartbroken girls must decide if they are willing to put love aside to save the school - and Christmas.