Yakusoku no Neverland tells the story of a group of orphans living at Grace Field House. They live a seemingly idyllic life, cared for by their loving caretaker, Isabella, whom they call "Mama."
The children enjoy their days playing and learning, but they are also subjected to daily tests. Every few months, a child is adopted and leaves the orphanage, supposedly to join a new family.
However, some of the older children begin to suspect that something is not quite right. They start questioning the true nature of Grace Field House and the disappearances of their friends. Their investigations lead them to uncover a dark secret lurking beneath the surface of their peaceful existence.
The anime focuses on the children's struggle to uncover the truth and their efforts to protect themselves and their siblings from the unknown dangers that surround them. They must use their intelligence and courage to survive in a world that is not what it seems.