Miss Granny (movie, 2014)

Oh Mal-Soon (Nah Moon-hee) is a 74-year-old widow that realizes she is becoming a burden on her family. As she is roaming the streets, she comes across a photo studio and decides to dress up for a self- portrait. When she walks out of the photo studio, she mysteriously turns back into her twenty year old self. Making the most out of this one in a lifetime opportunity, she changes her name to Oh Doo-Ri (Sim Eun-kyeong) and decides to make the most out of her youth.