Choi Kang Chi is half animal and half person. When he was a baby, he was taken in by a merchant named Park Mu Sol. Kang Chi has some strange power. Dam Pyeong Joon is the owner of the Invisible Knife Moo Kwan and a patriotic warrior. Dam Yeo Wool is his daughter. Kang Chi and Yeo Wool meet each other and fall in love. But their fathers don't like each other. Jo Gwan Woong betrayed his country. He uses his power to put honest people in trouble and make money for himself. Kang Chi always foils his plans to do something bad. So, he is sure that he will kill Kang Chi in different ways. Kang Chi is confused about who he is, but he stands up for what is right.