The directors wanted to make a supernatural tale without ghosts or scary scenes. But the producer refused the idea and they had to add some ghost scenes.
The directors prefer the English title "Memento Mori".
The main character's name Soh Min-ah is named after Gelsomina from La Strada.
The original rough cut of Memento Mori was about three hours long. However, due to complaints, about half of the footage was cut out over controversy relating to the films' LGBTQ+ nature. The original cut is exclusive to a special limited collector's edition DVD release (now OOP.)