The Man in Black first appears when Kazuma Kiryu goes to the Amano Building in Kamurocho while in search of a kidnapped Daigo Dojima, having been called there by his anonymous kidnapper. When Kiryu enters the building, the Man in Black attacks him, intent on killing him. Kiryu bests the assassin and continues on his search but; as Kiryu fights his way through the building, he is hounded by the Man in Black, who returns to attack him two more times before Kiryu reaches the kidnapper on the rooftop.
Later in the story, when Kiryu, Kaoru Sayama and Haruka Sawamura are returning to Tokyo to confront Yeongmin Ji, they are ambushed on the highway by a platoon of Jingweon assassins led by the Man in Black. Kiryu fights the Jingweon men on top of the trucks that they were using to chase them and ultimately duels the Man in Black once again, defeating him by throwing him off the truck and onto the highway.
Despite sustaining serious injuries from his fall, the Man in Black attacks Kiryu one last time when he is heading to the top of Kamurocho Hills to face off against Ryuji Goda. On the elevator ride to the construction site's top floor, the Man in Black jumps into the cargo lift and attacks Kiryu, only to be defeated once again and left unconscious on the elevator floor.
It is unknown what happened to the Man in Black after his third defeat. However, as Ryo Takashima would later kill several Jingweon men while making his way to join the confrontation atop Kamurocho Hills, it is possible that he may have been killed by Takashima.
The Man in Black is trained in taekwondo, employing multiple types of kicks and knee strikes as his primary means of attack. However, he also frequently uses quick punches and jabs to interrupt his adversaries' combos. He makes frequent use of the metal plates in his armguards and boots to block attacks.
During the third fight against him, he will use retractable blades hidden in his boots to incorporate additional slicing damage to his kicks.
- Unlike most other minibosses; whose name is provided in their health bar during the fight (even minibosses belonging to the Jingweon), the Man in Black's name is never revealed; being only referred to by his alias.