SPOILER ALERT: the following article contains massive spoilers, including the ending. If you have not yet seen the movie, proceed at your own risk, or better, come back to this article later!
SPOILERS AHEAD
Three Sisters Plot Summary and Synopsis
The awkward, distant, and wounded three sisters gather at their hometown for their father’s birthday. However, on the day of the party, there is a big mess because of their little brother Jinseob’s abnormal behavior, and the past of the three sisters slowly reveals.
Source: Wikipedia (CC BY-SA 3.0).