Yoon Hajoon, who struggled to pursue his musical career despite his iffy talents and ended up sacrificing his own family along the way, " If only I could turn back time...! " One day, after living with regrets and alcohol for a while, he woke up and found himself had returned to the past. Just then, it dawned on him. The fact that my younger sister is a musical genius...! Now is the time to turn my life around, that is by producing my younger sister into becoming the best singer!