Yasuo Kawasaki serves as a member of the Shinjuku-based mobile strike team within the Tokio Private Police force. He is defined by his intense enthusiasm for mechanized units, displaying minimal to no interest in interpersonal relationships or romantic pursuits. His exclusive focus remains on mecha technology and operations.

He demonstrates notable expertise by providing a detailed technical analysis of the "Crab Cop" unit. Yasuo excitedly describes its twenty millimeter vulcan cannons with three thousand rounds per minute capability, admiring its form as "perfect" and "more than a perfect mobile mecha," explicitly stating his desire to pilot it. His technical breakdown includes noting its maximum speed limitation of forty kilometers per hour, reflecting specialized knowledge and a near-obsessive appreciation for mecha engineering.

Within the team dynamics, Yasuo interacts with colleagues like Noriko Ibuki and Isamu Oyama. His singular passion for mecha defines his role.