The drama tells the story of the brother and sister's father, Takaji, who was killed at work as a police officer, and soon after, they decided to avenge their father after learning that the culprit was a cadre of Japan's largest special fraud organization, "Phantom Beast". The elder brother Takaichi Watarase was a former police officer and was full of a sense of justice and action, and his younger sister Takaki Watarase was an engineer at a national university and an excellent white hat hacker. The two use their respective specialties to infiltrate the organization and confront the great evil.