"My hand is holding one's hand, yet my heart holds another's - who holds the greater pain?"

A show that explores in detail about revenge and forgiveness. Guy on the right killed the elder brother of the guy on the left, 12 years ago, when everyone was still in their teens. The death coincidentally caused another death - the mother of the guy on the left. Unfortunately for him, the two deaths wiped out his entire family, and in addition, brought down the reputation of his family name. Thu, naturally, he vows to get even with the guy on the right, in due time. So, using 12 years, he single handedly planned his revenge.
Like all shows of this genre, as the story goes, the guy on the left gradually falls in love, and hangs onto the little piece of human soul still left within him. He is torn between fufilling his supposed destiny and acknowledging the existence of the only person who understood his pain.
A very common plot about revenge and forgiveness, but what makes this series unique and outstanding is the details.
The people needed to be killed for revenge was murdered under naturally occuring incidences and accidents that were cleverly maneuvered. There were no traces of anything that will evidently point towards the mastermind or threaten to surface his name. By the middle of the series, when every event starts falling into place, you'll realise that his plot for revenge moves like a chess game, and with each brilliant flawless move he makes, he gets closer to checkmate.
However, the director also captured the emotional parts of the series in an intrinsic fashion that makes the audience feel for the characters and what they would likely experience at different stages of the plot - especially for the guy on the right and the left. For example, in the early episodes, you will enjoy the victories with the guy on the left as his plot succeeds, but in the later episodes, when the plot starts involving more lives, and you see the guy on the right repenting deeply for his past actions, you start wanting the guy on the left to stop his plotting. I guess the collaboration between the director and the acting cast accurately displayed all the emotions through the different parts of the series.
I really enjoyed every bit of this show.