Ms Lim said her 'prettiest' classmates were selected to work for him and were taught to give him massages or even become his sex slaves.
They are taken away to work in one of his many boltholes and serve him luxury food, including caviar and other 'extremely rare delicacies', she claimed.
If they made mistakes or objected to their treatment they would 'simply disappear' - even if they became pregnant, she said.
She later suggested that Jong-un threatens war because he 'feels concerned' and has 'no escape'.
This file picture shows female North Korean troops using an anti-aircraft weapon in Pyongannam-do, north of Pyongyang Ms Lim, the daughter of an army colonel, alleged he has sex saves and hides in covert boltholes to make it impossible to trace him.