a coincidence that is...well, just too coincidental to really happen. typically found in Korean soap operas, music videos, and movies.
Regular coincidence: You have exact change for the clothes you're buying. Afterwards, you find a dollar in one of the pockets.
Korean coincidence: The store goes up in flames, so the cashier gives you an entire rack of clothing for free. Unfortunately, the store doors close at that exact moment, locking you and the cashier inside. Convinced that you are about to die, you kiss the frankly attractive cashier. The moment you do that, your girlfriend pounds on the store door trying to see if you're inside. She sees you, bursts into tears, and runs into a busy intersection. After firefighters pull you out of the fire, you see your girlfriend being pushed into an ambulance. You donate your organs to her so that she can function normally. She visits your comatose body in the hospital, and birds conveniently begin singing.
the belief that there is no higher truth or purpose and that everything is just the result of a highly unlikely chain of coincidence after coincidence, and thus there is no way of knowing what will happen, nor is there any reason to why it happens.