[3] A 70-year-old poet falls in love with a high school girl and is inspired to write a short story about her, but his star student, who is jealous of the relationship, steals his literary work.

Finding a young high schoolgirl, Eun-gyo, asleep on a chair on his porch, Jeok-yo, instantly enamored, agrees to give her a part-time job cleaning his home.

As Jeok-yo spends more time in Eun-gyo's company, long-lost feelings are awakened within him, and her exuberance, sense of fun, and genuine warmth towards him make him see himself as the young man he used to be.

[7][8][9][10][11][12] The novel, which revolves around a relationship between a poet in his 70s and a 17-year-old high school girl, had sparked heated debate as soon as it began to appear in serialized form on author Park Bum-shin's personal blog.

[8] Director Jung Ji-woo said he chose Park Hae-il for the role, instead of an older actor, for a specific reason, saying, "This movie deals with what it is like to age, and what it is like to want something when you've lost your youth.

Jung praised Park's "incredible tolerance," undergoing eight hours of special make-up daily and learning the weary gait and gesture of a man in his 70s.

[8][15] Kim Go-eun was a drama major at Korea National University of Arts who had never appeared in a film or TV series before, not even in a minor role, having only previously acted in student productions or school plays.

[13] Looking for an actress that "had to be ordinary and alive at the same time," Jung said he decided on Kim "by discussing the book and her personal thoughts about Eun-gyo [...] What I liked about Go-eun was that she didn't try to impress me at all.