Mr. Back (2014)

Mr. Baek is a successful hotelier who's more interested in hoarding his money than in enjoying his golden years. But in a strange turn of events, this classic scrooge gets a second chance at life when he wakes up as a younger version of himself (Shin Ha Kyun). With no way to prove his identity, Mr. Baek must enter his own company as a rookie and is forced to work his way up once again. With precious little time, Mr. Baek is given the opportunity to take stock of his life — and to give love a chance.