BLACKFOX follows Rikka Isurugi, a 16-year-old raised in the way of the ninja by her grandfather Hyoe in a hidden household within a futuristic city. She looks up to her father Allen, an esteemed researcher whose latest work has produced a set of cutting-edge drones with artificial intelligence and extraordinary technical capabilities. Allen intends to develop the machines for civilian use, but others see the technology as something far more dangerous.
That threat reaches the Isurugi family on Rikka's birthday, when a paramilitary group storms their home in search of the drones. The raid leaves Allen and Hyoe dead, while Rikka escapes with the machines and the trauma of losing both the people who shaped her life. Months later, she hides inside the routine of an ordinary girl, working as a private detective and sharing an apartment with Melissa. After dark, however, she puts on her grandfather's fox mask and begins hunting the people responsible for the attack. Driven by the anger she has carried since that day, Rikka turns her ninja training, her father's technology, and her own resolve toward a single goal: making sure her family's killers face justice.