He killed his entire family to reclaim power over them. But he spared a life of a young boy cause he knows that time will come that he will mature and will realize the bitterness of life. And someday, he'll seek revenge for his family. Now, that time came. He was hunting the person who killed his loved ones. A secret organization has been helping him. He treats the Master as his second father despite his hidden identity. But what will happen if he discovers the truth behind his Master's identity? Through the process of revenge, he meets a girl opposite of his personality. At first, he doesn't love her. He doesn't know her significance at all. But later on realizes what she's worth. But through this all, what can he do to protect her from danger? And upon knowing all the truth, can he still continue avenging his murdered family?