[1][2] Gullible yet cheerful Shin Ji-hyun (Nam Gyu-ri) is living a perfect life: she is the only daughter of wealthy, doting parents and is surrounded by supportive best friends.

She works third shift at a convenience store, sleeps in the afternoon, and often spends what little time she has left in the day contemplating suicide.

When she regains consciousness after the accident, she shockingly finds that she could neither make physical contact with the people crowding around her car nor could any of them hear her protests.

The offer is contingent, however, on the completion of a mission: Ji-hyun must gather three teardrops shed out of pure love by three people not related to her by blood within the next 49 days.

Ji-hyun proceeds by seeking employment as a waitress at a restaurant owned by her high school friend, Han Kang (Jo Hyun-jae).

This TV series was inspired by the Korean Shamanism "Bardo" that a soul usually wanders the earth for 49 days and then moves on to the next life, thus frequently referencing relevant Buddhism (once a majority religion of Korea) ideas such as reincarnation and karma.

The "unutterable secret of the heavens" (천기누설) that Scheduler speaks about is similar to the mysteries of the kingdom of God that "man is not permitted to tell" (2 Corinthians 12:4, Mark 4:11, Matthew 13:11).