Kim Soo-hyun is a mother whose young daughter Han Saet-byul gets kidnapped and murdered.
Discovering a miraculous ability to go back in time exactly two weeks before the event,
Soo-hyun is determined to expose the kidnapping plot and save her daughter before she dies
all over again. Helping her is Ki Dong-chan, a former cop turned private investigator out to
prove the innocence of his mentally challenged brother, who is falsely accused of murdering
Dong-chan's ex-girlfriend.
— based on Wikipedia
1 Korean variant