Sanda is set in a near-future Japan where a dramatic decline in the birth rate has reshaped everyday life. Children are treated as national treasures, watched over carefully by adults, and raised in boarding schools, while Santa Claus—the figure once associated with hope and gifts for children—has been recast as a dangerous presence marked for elimination.
On a snowy December 25th, middle school student Sanda Kazushige is suddenly confronted by his classmate Shiori Fuyumura. After learning that Sanda is a descendant of Santa Claus, she makes an impossible request and pleads, "Santa, please find my friend." Fuyumura is searching for her missing best friend, Ichie Ono, and believes Sanda may be the one who can help her.
Drawn in by her desperation and the fragile world around them, Sanda chooses to take up the role of Santa Claus. To protect the children, he sets out to fight against the adults who see Santa as a threat, stepping into a conflict that turns hope itself into something worth fighting for.
