Flower Grandpa Investigation Unit () is a 2014 South Korean television series starring Lee Soon-jae, Byun Hee-bong, Jang Gwang and Kim Hee-chul. It aired on tvN from May 9 to July 25, 2014 on Fridays at 21:50 for 12 episodes. Plot The lives of four detectives in their twenties are changed forever when after an experiment gone awry, three of them rapidly age overnight and find themselves in the bodies of old men in their seventies (only one, Park Jung-woo, emerges unscathed and stays young). As his suddenly much older colleagues comically struggle to deal with their new and unusual predicament, Jung-woo shares in their hardships, joining them in their mission to find a way to reclaim their lost youth. Meanwhile, the team also continues to solve crimes, while the "grandpas" work at a delivery service as their cover. Cast Main characters Lee Soon-jae as Lee Joon-hyuk (70s) Choi Jin-hyuk as Lee Joon-hyuk (29) Shin Dong-woo as teenage Lee Joon-hyuk The brains of the operation. He has a photographic memory and never forgets a single detail, and is widely known in the precinct for being cold-hearted and selfish, who probably wouldn't even bleed if you pricked his finger. But one day he works a strange case, and wakes up having aged fifty years overnight. Suddenly he can't remember even the simplest details because he's battling senility. And he has to watch helplessly as his fiancée questions why her boyfriend just vanished into thin air three months before their wedding. Kim Hee-chul as Park Jung-woo (29) The precinct's golden boy, the only son of the chief of police who was born with a silver spoon in his mouth. He's the only one who escapes the aging spell. Byun Hee-bong as Han Won-bin (70s) Park Min-woo as Han Won-bin (29) The Casanova of the group, who pretty much skates by in life with his looks and charm. But when he wakes up as an old man, he finds his face covered in wrinkles and doesn't know how to function when he can't get anyone — even ajummas — to look his way. Jang Gwang as Jeon Kang-seok (70s) Park Doo-shik as Jeon Kang-seok (28) The youngest of the group at 28, he's a former national boxer. Of course in an elderly body, he finds that he can't kick anything without throwing out his back. Supporting characters Lee Cho-hee as Jung Eun-ji, female