A young woman who works as a book-reading YouTuber falls asleep while reading and is possessed by the book she is reading.

Waking up inside the tyrant's bedroom, she tells him what she needs to do to stay alive, and he falls asleep while listening. From then on, she becomes the tyrant's insomnia therapist.

In order to escape from the tyrant, she must cure his insomnia, but as she does, the tyrant becomes obsessed with her...