Fan Casting You (Korean series)

What would you do for love? For a brilliant male bookstore manager who crosses paths with an aspiring female writer, this question is put to the test. A charming yet awkward crush becomes something even more sinister when the writer becomes the manager's obsession. Using social media and the internet, he uses every tool at his disposal to become close to her, even going so far as to remove any obstacle --including people -- that stands in his way of getting to her.