A false confession manhwa novel is interesting because it plays with your expectations. You think you know what's going on based on the confession, but then things start to unravel and reveal a much more complex story. The element of surprise and the exploration of truth make it compelling.
First, you need to have a great story idea. Then, do some research on the style and format of manhwa to get a sense of what works. Sketch out your characters and plan the plot.
You might start by looking at bestseller lists in the genre related to the manhwa. Or, check out novels by authors who have a similar writing style or approach to storytelling as the manhwa creator. Another idea is to browse reviews on book websites to find novels that match your preferences based on the manhwa.
Well, first off, characters are crucial. You need a likable protagonist, perhaps a student who's a bit of an underdog. And a love interest that has some mystery or charm. A common setting could be the school campus or a study group. Also, the initial 'false start' could be a misunderstanding between the two main characters, like one thinking the other is snobbish when they're just shy.