Directed by Lee Yoon Ki, the poster presented Kang Soo (Kim Nam Gil) and Miso (Chun Woo Hee) walking together on a bright, sunny day.

Miso's transparent silhouette lets viewers know she is, in fact, a spirit. The caption reads, "Can you see me?"

'One Day' is set to be released in April and tells the story of an insurance investigator who recently lost his wife. When one day, he encounters a ghost who is only visible to him...