It's Christmas 2012, and Sun Woo surprises his mother and his best friend with a gift and a secret. His actions in the past begin to affect his present and his memory.

Now with his brother happily married and alive, Sun Woo must face the consequences of no longer having Min Young by his side.

Sun Woo's illness worsens with each travel back in time, but he's still determined to save his father's life.