When three gifted kids at an isolated idyllic orphanage discover the secret and sinister purpose they were raised for, they look for a way to escape from their evil caretaker and lead the other children in a risky escape plan.

At Grace Field House, life couldn't be better for the orphans. Though they have no parents, together with the other kids and a kind "Mama" who cares for them, they form one big, happy family. No child is ever overlooked, especially since they are all adopted by the age of 12. Their daily lives involve rigorous tests, but afterwards, they are allowed to play outside. There is only one rule they must obey: do not leave the orphanage. But one day, two top-scoring orphans, Emma and Norman, venture past the gate and unearth the harrowing secret behind their entire existence. Utilizing their quick-wittedness, the children must work together to somehow change their predetermined fate.—MAL Rewrite

Emma, Norman, Ray, and many other "siblings" live at an isolated orphanage cut off from the outside world. They live a charmed life surrounded by friends and watched over by Mama, their caretaker, until they leave the house for a foster family by the age of twelve. The only rule is that they must never venture outside of the gate that isolates them from the rest of society, for dangers await. But one day, the children learn the true horror of what's in store for their short lives...

The orphans at Grace Field House have only ever known peace. Their home is nice, their bellies stay full, and their caretaker, Mom, loves them very much. But their world turns upside down when the smartest children of the bunch--Emma, Ray, and Norman--learn what horror awaits them on adoption day. Now, their cultivated wit may be their only chance of survival.

As much as the children love her as their mother, she is not their parent. Although the children live together as siblings, they are not related. Grace Field House is where children without parents live. An irreplaceable orphanage for 38 children who all live seemingly perfect lives every day with their caretaker and mom, Isabella. However, the happy days at Grace Field House turn out to be a false paradise. In truth, their home isn't an orphanage, but a farm, and the children aren't orphans, but cattle, destined to be slaughtered and sold as human meat for demons. Meanwhile, the mom they love is actually a watchdog working for the demons.