My Ordinary Love Story (2014)

Both contains black comedy elements juxtaposed against the lighter elements of the story

Both Mk are essentially nice people

Both are south korean thriller films with horror elements that focus on a female main character. Her past experiences with men havent always been positive so shes rather concious about them. In both theres also a nice sismance. They share the same director so they have a similar vibe too and... this is a spoiler for my ordinary love story: ... theres a male serial killer in both.

They both are thrillers (Watching is more obvious about it haha) and they both also have a ml who isn't very normal and who "loves" the fl (who is btw played by the same actress in both movies). The movies also have a plot twist (one stronger than the other) which makes the story even better.