Trigger warning, this is a series that contains scenes with heavy violence, bullying and abuse.

This is the story of two men, one of whom, Kyung Min due to certain circumstances, finds himself remembering what he went through as victim of school bullying, he is a man who lives with the trauma of what happened to him and this triggers in him a thirst for revenge and retribution. So, mysterious serial killings begin to occur.
Meanwhile, Detective Jong Suk, childhood friend of Kyung Min, also a victim of school violence, finds himself linked to these revenge murders.

I believe that the word of this story is : tragic. The drama touches on the origin of school violence and the bullying that pervades modern society.
The show doesn't spare our feelings as the subject is not treated and portrayed lightly. A lot surrounds the physical, sexual and mental abuses that these young children suffered, and all that, under the eye of teachers and parents who are aware and sometimes even participated in it.

I don't want to reveal what the plot contains, but know that I binge watch the show, it was captivating. The production and the script are excellent, the tones are dark and we follow each stories with impatience, especially when the flaskbacks occurs. It's very well executed, we discover new perpetuators and twists in each episode, it's quite the ride.

The series also touches on revenge, there are so many shows out there especially in the thrillers which use this subject, but it was really enticing here. Of course, we does dip into the dichotomy of justice with those who prefer the law of retaliation, including the reciprocity of crime and those who firmly believe that justice is done by laws.
Unfortunately, the human made laws are far from reflecting what one would like justice to be, and many take advantage of this flawed system and are never punished.

I could feel that terrible disbelief and despair coming from Kyung Min, when he was facing his abusers, and those people don't even remember what they did to those poor children or for them it was only "jokes" between children and that it was "good times".

Talking about the actors, I must say they did a phenomenal job, Kyung Min in his search for revenge, he wants to make things right "according" to what was supposed to happen twenty years ago, and Jong Suk who has buried what happened and refused to face it. Both actors gave us excellent performances.

It's a series that makes you think, I don't recommend if you're sensitive but for lovers of korean revenge thrillers and psychological crime, it's for you.