Hirofumi Takatori is the second son of Reiji Takatori, a member of a prominent and politically ambitious Japanese family. His background is defined by privilege and a deep loyalty to his father, whom he is determined to help become Prime Minister.

Hirofumi possesses a profoundly cruel and sociopathic nature. He organizes human hunts, kidnapping young women and other victims to use as prey, delighting in the murder and violence. Despite this brutality, he shows a complex and seemingly sincere affection for his younger brother, Omi, expressing happiness and sadness when they are reunited and claiming to have missed him. However, this sentiment is conditional and self-serving. He is ultimately a coward who shows true fear only when his own life is in danger, and he displays complete indifference to the deaths of others.

His primary motivation is advancing his father's political career, viewing the horrific human hunts as a means to secure political points and support. He expects his brothers to share this goal and help make their father's dreams come true. In the story, Hirofumi serves as a primary antagonist, directly opposing the efforts of the assassin group Weiss. His actions, particularly the human hunts, make him a target of Persia, the group's handler.

The most significant relationship is with his brother Mamoru, known as Omi. While they played together as children, and Hirofumi appears genuinely moved to discover Omi is alive, this quickly turns to suspicion and violence. He becomes fixated on discovering who is employing Omi as an assassin, to the point of having him kidnapped and brutally beaten for information. He also forms a key, though ultimately treacherous, alliance with the telepath Schuldig, relying on him for protection when Weiss attacks.

Hirofumi demonstrates little capacity for change or redemption. He ignores Omi's pleas to confess his crimes to the police and remains committed to his violent path. His development is one of increasing desperation, culminating in a final, failed attempt to kill his own brother by driving his car directly at him. His notable abilities are not superhuman but lie in his political connections, his organization of illegal hunts, and his use of weapons like guns. He is ultimately shown to be a coward who relies on others, such as Schuldig, to protect him when he is directly confronted.