There were two families. One Ji sook’s and other Min woo’s. One was happy even though they had nothing and the other was unhappy with everything. And then Ji sook joined Min woo’s family and changed Min woo into a happy person.
Just like Min woo and Ji sook there’s another couple, Seok hoon and Mi yeon. They never thought they were wrong. They only wanted their own happiness and the rest of the world can be sad and they wouldn’t care but when they were unhappy they made plans for the others to be unhappy as well. But sometimes God makes plans and humans just can’t go against it, can’t blame anyone and has to accept the defeat.