Sad movies I've watched this year (totally recommended):
 

1. Secretly Greatly

Synopsis:
As a North Korean sleeper cell agent, Ryu-han infiltrates the South and assumes the role of a village idiot in a rural town. He observes the townsfolk and waits patiently for his mission. One day, after 2 years of playing the role of the village idiot, fellow elite spies Hae-rang, posed as a rock star and Hae-jin, posed as an ordinary student, are dispatched to the same town as Ryu-han. He helps the other two spies settle in and teach them how to adjust in the South. There is a sudden drastic political power shift in the North and all three spies receive an urgent mission: commit suicide.

2. Miracle in Cell no. 7

Synopsis:
Successful Ryoo Seung-yong comes back as a fool for his daughter!
Outsiders not allowed! In room 7 of the prison where all kinds of criminals are gathered, comes Yong-gu, a father with the sense of a 6 year-old and his 7 year-old daughter Ye-seung.
The mission of these criminals in room 7 is to protect these two who can never stay apart for a single moment.

3. Into the Fire

Synopsis:
A story of 71 student soldier trainees who fought an impossible war against seasoned North Korean army during Korean War which broke out in 1950. Based on real history, the film delicately depicts the fierce battle that teenage student soldiers fall into as they fight to protect the final defense line by themselves when under a surprise attack and their emotions and conflicts as they experience the grown-ups’ war.

4. Daisy

Synopsis:
An elite Interpol agent Jeong-woo and a ruthless hitman Park-yi, both stationed in Amsterdam and are in love with the same young woman, Hye-young. Hye-Young is a simple sidewalk artist, with dreams of one day holding a real exhibition in a real gallery. Her pure love will draw these deadly men into a spectacular showdown in the process, revealing Hye-Young¡¯s hidden past.