When Irene celebrated her 18th birthday, she wished to live a life full of surprises. In hopes of escaping her boring and predictable life, she rebelled against her parents and joined her friends to their summer getaway trip in Jeju Island. 

The gang had just come from an island-hopping trip and were on their way to the airport when an accident changed their lives forever. Irene woke up from a coma after 365 days and received the worst birthday gift of her life: unexplainable physical changes and the ability to see a weird ghost named Chanyeol who promised to haunt her forever.

As Irene becomes closer to her supernatural friend, she discovers his identity and the secret behind his death. How will this secret connect Irene and Chanyeol's fate? "She dug too deep, now she can't get out." How did their story end? Irene is walking down the aisle.