Dae-su, who once showed promise as a taekwondo athlete despite his “ineffective swing kick,” and Mira, who aspired to be an idol, found themselves unexpectedly becoming parents at 17. Now at 33, they have a 16-year-old son named Ahreum. Ahreum suffers from progeria, a rare genetic condition that causes him to age much faster than usual, giving him the appearance of an 80-year-old man despite his young age. Despite the challenges and negativity they face, this close-knit family perseveres, living life one day at a time. Everything changes when Ahreum’s story is featured on a national TV program, thrusting him into the public eye and transforming his previously uneventful days into a mix of happiness, joy, and sorrow.