At first glance, everyone would really think that the story is about mother/daughter relationship. I think that way too
when I first saw the MV, but then I've read in the comments about the accident and I looked it up. Then I realized there's
more to the story than what we are seeing.

On April 16, 2014, MV Sewol ferry gave a distress signal on South Korea's coast.The ferry is said to be in a trip from Incheon port going to Jeju. In the report, it is accounted that out of 459 passengers, 325 were students of Danwon High School having a school trip as a break before their last year, when they must take college entrance exam. Many are missing and probably had drowned. According to NBC News, 304 were victims of the sunken ferry. After reading the article. It made me realize that the MV is somehow a tribute to it. Now this song breaks my heart even more.

Source:

http://www.nbcnews.com/storyline/south-korea-ferry-disaster/south-korean-ferry-capsizes-sinks-hundreds-missing-n81721 http://www.nytimes.com/2014/04/17/world/asia/south-korean-ferry-accident.html?_r=0