Akutaro Shindo, often referred to as the Emperor, is the leader of the NG Boys, a gang that distinguishes itself through its use of cunning and underhanded tactics rather than direct, honorable combat. His history is deeply tied to the rival gang Minato Kai, from which he was banished approximately six months prior to the events of the story following a conflict with Kenichiro Doman, the respected head of that group. Before his expulsion, Akutaro was a thin and unreliable individual who greatly admired Kenichiro for his strength and manly demeanor. This banishment served as a catalyst for a dramatic transformation, turning him into a violent and vengeful figure.

In terms of personality, Akutaro presents a flamboyant and devious demeanor, often appearing to take genuine pleasure in his own chaotic and sadistic schemes. He is highly manipulative, as seen when he feigns friendliness towards the protagonist, Arajin Tomoshibi, in order to learn his weaknesses and gain his favor. His cruel nature is further highlighted by a willingness to exploit others without remorse, even suggesting horrific fates for his enemies, such as the enslavement of Mahoro. This raises questions about the source of his more extreme eccentricities, as he is later revealed to be fused with Ichiya, a powerful and malevolent blue genie, making it ambiguous how much of his behavior stems from his own will and how much is the influence of this entity.

Akutaro's primary motivation is revenge against Minato Kai, the group that cast him out. To achieve this, he orchestrates a complex scheme to instigate a full-scale gang war between Minato Kai and the Siguma Squad, hoping to have them destroy each other. He sees potential in Arajin, attempting to recruit him into the NG Boys, while simultaneously using his gang members to provoke and manipulate the other factions. His role in the story is that of a principal antagonist whose machinations drive much of the central conflict, forcing other characters into confrontations they might otherwise avoid.

Akutaro is a capable fighter, though his style is notably different from the brawling approaches of other characters. His weapon of choice is a whip, which he controls with great precision, using it to keep opponents at a distance and inflict severe pain without granting them an opening. He is also quite agile, able to hold his own in combat against individuals like Zabu Kakeru and even Arajin when he is empowered by his own genie, Senya. His bond with the blue genie Ichiya is a crucial aspect of his character, and he has the ability to use Ichiya's power to mind-control others, a tactic he employs to build his army of followers in the NG Boys. The full extent of his abilities and the nature of his relationship with Ichiya remain complex, as it is unclear whether he is merely a host for the genie or a willing partner in their shared malevolent goals.