Act Your Age (The Promised Neverland)

Everything was supposed to be perfect.
They spent months planning out how they wanted their prom night to go. A night full of silly dances and boisterous laughter followed by a weekend of morning shopping trips and late night conversations.
Unfortunately, that's not what is going to be happening tonight.
And no one knows that more than the two girls forced to flee into the woods behind the prom venue before it even began...

Or in short,

Two childish teenage girls teach a group of children that grew up too fast how to be kids(because we all know that they need it.)