Living a precarious life as a part-timer at a convenience store, Ae Ri strives to support her mother who is on a waiting list for a heart transplant. Unfortunately, her mother’s worsened physical condition leads her to forgo the long-awaited opportunity for the transplant, and just like that her mother disappears. Things were already chaotic enough for Ae Ri when she receives a phone call from a strange man claiming to befrom the same world but 31 days in the future. Ironically, he desperately asks Ae Ri for help.
Seo Jin, a father and a husband of a close-knit family, has been living a successful life as the youngest person to become a director at a construction company. One day, it all crumbles down with the unauthorized takingping of his daughter and his wife’s self-harm. On the verge of breaking down, he is given an opportunity to restore everything that was lost under one condition, help from a strange woman. To bring his daughter and wife back to life, he makes a phone call as the clock strikes 10:33.