Yoo-tan, a struggling indie musician, breaks up with his longtime girlfriend Da-in and wakes up to find that the same day is repeating over and over. Trapped in a time loop, he relives ordinary moments until he begins to notice what he has taken for granted. Through music, regret, and small repeated choices, he learns what truly matters and how to reclaim a future he almost abandoned. The musical blends light comedy, warm sentiment, and modern pop-style numbers.