Follows a weak and timid son born into a fishing family and seeing his father killed by a "water monkey" monster when he went fishing with his father as a child, it left an obsession in his heart. Ten years later, the monster "Water Monkey" reappears, killing the heroine's younger brother and father. In order to save the woman, the male lead did not let the women killed as "sacrifices". He began to learn the fishing and water skills his father had taught him. He also invites his cousins ​​to train and fight together. The villagers also realized their mistakes and joined the underwater monster team. Finally, everyone eradicated the water monkeys, the villagers returned to a normal life.