In a near-future Japan with ultra-low birthrates, children are cherished but closely monitored. Santa has been banned as a threat. On a snowy December 25th, middle-schooler Kazushige Sanda, a descendant of Santa, is confronted by classmate Fuyumura, who asks him to find her missing friend, Ono. "Santa, please find my friend." To shield children from adults, Sanda decides to take on the role of Santa and confront the adults.
