Mr Baek

Go-bong Choi is an old man with a troublemaker son named Dae-han; Hae-soo Eun gets hired as an intern at his hotel but gets fired after a misunderstanding with Dae-han.

Go-bong goes back to his younger days while he takes a shower and walks out naked in front of Ha-soo; Ha-soo runs away from the house thinking it is Dae-han who is walking around naked.

Shin-young infiltrates his company as a cleaning worker, while Dae-han tries to catch him and find out what really happened to his father.

Ha-soo is mad that Shin-young lied to her about his whole life and hid the fact that he's the chairman's son; Dae-han orders a new DNA test and the results come back 100% match.

Elderly CEO Choi Go-bong suddenly becomes thirty again.