Yoshitsune Miyamoto, known as Yoshi, spearheads Landmate engineering and design for Olympus' elite ESWAT unit. As a second-generation Bioroid—a genetically crafted artificial human—his specialized focus lies in developing and maintaining advanced mechanized combat suits, including tailored modifications for cyborg operatives such as Briareos Hecatonchires. His persistent fascination with analyzing Briareos' cybernetic systems underscores his drive to enhance ESWAT's tactical edge, though Briareos usually declines these offers.

Yoshitsune's duties reach past mechanical design; he actively supports field operations by delivering vital technical assistance during missions. This encompasses deploying repair systems for compromised equipment and answering distress calls from operatives in combat. His workshop functions as a critical center for ESWAT's hardware development and maintenance.

His bond with the Bioroid Hitomi reveals emotional facets defying typical bioroid limits. He exhibits protective care for her well-being and openly recognizes Bioroids' potential for affection, albeit at a diminished intensity relative to humans. This connection sometimes emerges through subtle cues, like Hitomi showing possible jealousy during his professional interactions with other ESWAT members. Their dynamic remains a consistent thread throughout his story.

Within Olympus' hierarchy, Yoshitsune balances technological innovation with tactical operations. His designs directly boost ESWAT's combat effectiveness, particularly through refinements to the Landmate systems and related military hardware. As a Bioroid strengthening a human-dominated security force, his role inherently navigates the societal friction between humans, cyborgs, and artificial beings in post-war Olympus.