Well, that took forever. I must have tried twenty different solutions before I came up with the right one. Still, it's far from being the worst puzzle I ever played. If you get stuck, make a big X.
What an utterly unsatisfying waste of time these pattern hanjies are, especially when they have absolutely no logic to them to add insult to injury. The only puzzle here is in trying to figure out what the point of creating it was in the first place.