Honestly, I don't have a definite answer. It could be based on a true story that was transformed and fictionalized to make it more engaging for the audience. Or perhaps it's a combination of multiple real incidents mashed together.
Well, it could potentially be inspired by a real-life event that happened in a particular community but the details might be kept private. Maybe it's related to a social issue or a hidden story that needed to be told.
I'm not sure exactly. It might be based on some local urban legend or a personal experience of the author that hasn't been widely disclosed.