[TOMT][Movie][2010s] A society locks away the children until they are 18

Hello, I remember a dystopic movie where, to protect the children, they would lock them away in a facility out of society until they turned 18. They would then enter society clueless.

They would probably be living in their own capsule, but I also have this idea of them being sedated for 18 years inside robot costumes.

Don't know if this is an actual movie, an anime, or just a movie concept

Thanks!