[2] Na Moon-hee stars as a woman in her 70s who magically finds herself in the body of her 20-year-old self (Shim Eun-kyung) after having her picture taken at a mysterious photo studio.

Through a magical shift between old and young, the film suggests that while modern society offers women more opportunities for self-expression, they still struggle for true agency.

On the day she is told by her son that she is being sent to a nursing home, the dismayed Mal-soon wanders the streets and comes across a mysterious photo studio that claims it captures the moments of one's youth.

As the "suspicious girl" of the Korean title, all anyone sees is that Doo-ri speaks with a regional accent and walks like an old lady, and that she acts very strangely and motherly for her age.

After wowing a group of pensioners with a stirring karaoke tune one day, she attracts the notice of her unknowing grandson Ji-ha, a 4th year in university, and Han Seung-woo, a TV music producer.

[13] By its second week, good word of mouth caused ticket sales to rise 106%, and Miss Granny became the surprise chart topper after accruing 1.76 million viewers over the Lunar New Year weekend.

[20] To date, the film has had 8,656,417 admissions, earning ₩62.5 billion (US$61.8 million);[21] it climbed to number 13 on the all-time Korean box office chart in its eighth week.