18 Again

Jung Da Jung and Hong Dae Young have been married for almost two decades, raising their twins together. Despite appearances, their life is far from ideal, filled with Dae Young's incessant nonsense. When he gets fired and Da Jung can't take it anymore, she files for divorce. This drastic step forces Dae Young to reflect on his life and all his regrets. Suddenly, he transforms into an eighteen-year-old with the same middle-aged mind. Renaming himself Ko Woo Young, he enrolls in his children's school, gaining a new perspective on life.
(Source: MDL)
~~ Remake of the American film “17 Again" [2009].