Daisuke Aramaki serves as the Chief Executive Director of Public Security Section 9, the covert counter-cyberterrorism unit within Japan's Ministry of Home Affairs. He holds the rank of Lieutenant Colonel in the Japan Ground Self-Defense Force, reflecting a long history within military intelligence before moving into public security. His background in Ground Self-Defense Force intelligence has given him deep connections within the military, a resource he frequently leverages to navigate the complex political landscape surrounding his department.

Physically, Aramaki is a short, unassuming man who traditionally dresses in standard business attire rather than the tactical gear of his field operatives. Unlike most of his team, who are full-body cyborgs, Aramaki remains almost entirely human, with the only cybernetic modification being his cyberbrain. This lack of augmentation makes him one of the few "fully human" members of Section 9, alongside Agent Togusa. In some storylines, he is shown using a cane as a result of being forcibly drugged while investigating a narcotics case.

Personality-wise, Aramaki is known for being a strict and demanding superior officer. His subordinates often informally refer to him by nicknames such as the "old ape," a reference to his facial features in the original manga which resemble a cross between a man and a monkey. Beneath this gruff exterior, however, lies a fierce loyalty to the members of his team. He is consistently depicted as a father figure to Section 9, willing to put his own political career and personal safety on the line to ensure the survival and integrity of his agents. While he despises political interference and corruption, he is not naive; he is a shrewd and pragmatic strategist who is not afraid to get his hands dirty in the political arena to protect his unit, frequently engaging in backroom deals and bargaining with high-ranking officials, including the Prime Minister.

The primary motivation for Daisuke Aramaki is the eradication of crime and the protection of Japan from cyber-terrorism and political corruption. He has a strong sense of justice that governs his actions. This sense of duty is deeply personal. Following the death of his granddaughter due to terrorism in some continuities, he is driven to prevent similar tragedies. His motivations are also tied to his mentorship of others; he sees the potential in operatives like Motoko Kusanagi and works to provide the framework for her and the rest of Section 9 to operate effectively.

In the story, Aramaki functions as the strategic anchor of Section 9. While Motoko Kusanagi leads field operations, Aramaki manages the political fallout, secures funding, obtains legal authorization, and uses his extensive network of contacts to gather intelligence that the field agents cannot reach. He is the shield that protects Section 9 from disbandment by hostile politicians, such as when he successfully negotiated the team's reinstatement after a political conspiracy led to their temporary dissolution. He is rarely seen in direct combat, preferring to exert his influence through diplomacy and strategy, though live-action adaptations have shown him to be capable with a firearm when cornered.

Several key relationships define Aramakis role. His relationship with Major Motoko Kusanagi is one of deep professional trust and mutual respect. He recognized her talents early in her career and recruited her, and he consistently supports her unorthodox methods while trusting her judgment implicitly. He also shares a significant friendship with Kubota, a powerful figure within the Ground Self-Defense Force, a connection that often provides critical support for Section 9's operations. On a personal level, Aramaki has a complex family history. He has a twin brother named Yousuke Aramaki, from whom he was separated; his brother later becomes involved in aiding refugees. It is also implied that Aramaki was once married, and in some continuities has children and grandchildren, though his dedication to his work may have contributed to the end of his marriage.

Aramakis character has shown significant development across the timeline of the series. In the Arise prequel, he is depicted as a middle-aged officer working to establish what would become Section 9, demonstrating his early political friction with other security organs. Following the events of the first Stand Alone Complex series, he suffers a professional setback but uses his cunning to get the unit reinstated in 2nd GIG. Later in Solid State Society, it is revealed that he was once the student of a powerful military general, Colonel Tonoda, whom he ultimately helped imprison for corruption, showing that his loyalty to justice supersedes even his personal mentorship bonds.

Regarding notable abilities, Daisuke Aramaki possesses no superhuman physical strength or cybernetic enhancements. His greatest assets are his intelligence, his deep well of political and military connections, and his masterful strategic thinking. He is an expert negotiator and a savvy political operator capable of outmaneuvering enemies far more powerful than himself. He is also highly perceptive and a capable judge of character, skills essential for managing a team of unique and highly independent personalities like those in Section 9.