Hasheem is a member of the Musashino Saru, one of the many youth gangs, or tribes, that control different territories in an alternate version of Tokyo. As a loyal soldier of the Saru, his actions are central to the escalation of the conflict that drives the story forward.

Hasheem is a close ally of Kai, the protagonist, and operates under the leadership of Tera, the respected head of the Musashino Saru. The character is part of a core group of friends within the tribe, which includes Steno and Kai, with whom he shares a strong bond of loyalty.

The character's main role in the narrative begins when he accompanies Kai and Tera into the hostile Bukuro territory, the domain of the rival Wu-Ronz gang. Their mission is to rescue their abducted comrade, Kim, an act that directly provokes the simmering gang war. During this incursion, Hasheem is present for a major confrontation, where the Saru leader Tera is seriously injured in an ambush by the Wu-Ronz and their leader, Mera.

Following this attack, Hasheem becomes a key figure in a subsequent, fatal clash. As he guides Kai to safety, Mera reappears and attempts to kill Hasheem. In a desperate attempt to shield his subordinate, Tera intervenes but is beheaded by Mera. This traumatic event profoundly affects Hasheem, who is consumed by guilt for his role in the death of his mentor and leader. The weight of this responsibility drives him to a state of deep despair, culminating in a suicide attempt.

Beyond his role in the story's violence, a small glimpse into Hasheem's personality is provided by a recurring, more lighthearted frustration: he is frequently unsuccessful in his romantic pursuits, a characteristic that persists even as the violent events of the tribal war unfold around him.

While specific details regarding unique fighting abilities are not the primary focus, Hasheem is portrayed as a capable and active participant in the gang's violent conflicts. His primary combat skill is his proficiency with firearms, which he uses in the gang's street-level battles against their rivals. His true value, however, lies not in his fighting prowess but in his steadfast loyalty to the Saru and his deep, unwavering friendship with Kai, defining his role as a steadfast companion in a brutal and unforgiving world.