The Puppet (2013)

From Mental Block

The Puppet is a 2013 Korean horror movie about a renowned psychiatrist who gets involved with the darker side of one of his patients that reveals itself once hypnotized.

A psychiatrist looks into the condition of his friend's fiance. He then uses hypnosis to bring out her hidden personality to investigate further. However, the hidden persona seduces him which he eventually falls for.

This causes him to break professional protocol and hypnotizes her to come to him every Sunday at 3 o'clock.

A female student is put under hypnosis as part of a demonstration
She goes back into a trance, triggered by the posthypnotic suggestion