Spiritpact (2018)

Both are super similar in that one of the male leads is an exorcist who is fated with the other male lead, who can communicate with the supernatural or is a ghost themselves. The two leads have a comical relationship at first, which then becomes more serious as the plot progresses. In both movies, the leads are bound together by a contractual relationship of some sort.

Both are based off of BL manga, but have been turned into bromances for the movie version. Some of the characteristics are still noticeable though, such as a degree of possessiveness and long gazes, touches etc.

Both are very similar in terms of featuring the supernatural, ghosts, exorcisms (i guess) and bromance.

Both dramas operate on the underlying theme of one male lead who sees ghosts and a second male lead who exorcises them.

Ferryman is somewhat like a darker, deeper version of Spiritpact in many ways - there are a lot of the same vibes and themes.

Ferryman is about a young man who has seen ghosts his entire life and ends up being recruited by a Grim Reaper for his skills. In a later season, he actually ends up in an official contract with the Reaper (Zhao Li) to catch ghosts before he can be given the opportunity to return to a mortal life.

Both films have a secondary female lead who is somewhat a romantic periphery interest but that romance theme is extremely subdued.