The Watching summary:

Mi-hun is a loner. He doesn't get out of the house after his parents' deaths. But after his encounter with the mysterious raincoat wearing man from the next door that just moved in, strange things starts happening in his dull and repetitive life. He finds out that the unexplainable 'spontaneous human combustion' incidents that are happening in his town are somehow connected to that raincoat man. He can't help spying on his new neighbors, but that turns out to be the biggest mistake in his life.