Kôsuke Sawamura is a supporting character in the science fiction series Moonlight Mile. He is introduced as a colleague and occasional rival of the protagonist Gorou Saruwatari, working within the Japanese space development program. Sawamura is a skilled engineer or technician, closely associated with the Moon Walker project, a mecha designed for lunar construction. His background includes having a younger sister named Chika, and he maintains a strong bond with her. Personality-wise, Sawamura is depicted as quick-tempered and sensitive, especially regarding his age or appearance; he reacts irritably when Gorou makes offhand comments about his looks or when his birth year is mentioned. This defensive attitude often leads to comedic bickering between the two men, yet their relationship is fundamentally one of mutual respect and professional camaraderie. Sawamura's motivations are rooted in his dedication to the space program and his desire to prove his competence, though he is also shown to have a playful, if easily provoked, side. His role in the story is to serve as a grounded counterpart to Gorou’s more reckless enthusiasm, occasionally providing technical support or personal friction. Over the course of the narrative, Sawamura demonstrates competence in handling advanced machinery and participating in high-stakes space operations, though his development is limited compared to the main protagonists. His notable abilities include engineering expertise and operational experience with lunar construction equipment, as well as a stubborn resilience that surfaces under pressure.