Sanda Ichigidai lives a quiet, strictly regulated life as a middle schooler in a future where children are a rare and precious resource, until the day his classmate Shiori Fuyumura attacks him with a kitchen knife. This startling confrontation, at the heart of the series also known by its Japanese title SANDA, unearths a supernatural lineage that the boy never suspected: he is the direct descendant of the legendary Santa Claus. The inciting ritual reveals a reality-bending twist, as Sanda finds