Mikihisa Komaki is a twenty-seven-year-old Library Officer Second Class serving in the Library Task Force, where he holds the rank of sergeant and acts as the assistant captain of Team Dojo. He is one of the instructors responsible for training new task force members, most notably Hikaru Tezuka, whom he mentors directly. Komaki is often described as a "giggling logician" because he maintains a consistently cheerful, pleasant demeanor while simultaneously possessing a sharp, analytical mind. He is frequently seen smiling or laughing at the interactions between his colleagues, especially at the dynamic between Iku Kasahara and Atsushi Dojo, and he enjoys offering them advice on both professional and personal matters. Despite his easygoing exterior, he is a capable and dependable officer who takes his duties seriously and is respected by his subordinates.

Komaki's background includes a close childhood friendship with Marie Nakazawa, a young woman from his neighborhood who is several years younger than him. When Marie develops a hearing disability during her high school years, Komaki remains a steady source of support, regularly selecting books for her to read. This relationship is central to his role in the story of Library Wars: Book of Memories, as his recommendation of a novel to Marie leads to his arrest by the Media Betterment Committee under the accusation that the content is unsuitable for a disabled minor. His arrest becomes a major crisis that galvanizes the Library Task Force into action.

Komaki's motivations are rooted in a deep personal commitment to living an honest life. He has resolved never to lie, a principle inspired by Marie's own pure and straightforward nature. This conviction is demonstrated when he refuses to participate in a plan to deceive Kasahara's parents about the nature of her work. His dedication to truthfulness and his protective feelings toward Marie eventually lead him to acknowledge that he no longer sees her as a child, revealing a genuine emotional attachment. Within the task force, his primary role is to act as a steadying influence on Dojo, his classmate and best friend, often soothing and tempering Dojo's more excitable tendencies. His strengths include strategic thinking, martial arts proficiency, and a keen intuition that allows him to anticipate the movements of opponents. He is also noted to be skilled at housework and attentive to the well-being of those around him, such as when he cares for Dojo during a hospitalization.