Children...

In 1991, five kids told parents they'd catch frogs on a mountain nearby. They vanished, the case became known in Korea as the "frog children disappearance."

Children... is a 2011 mystery thriller movie directed by Kyu-maan Lee, starring Ryu Seung-ryong, Park Yong-woo, Sung Dong-il. It holds an IMDb rating of 7.1/10 from 3,214 votes and runs 2h 12m.