Atsurou Masaki is the Chief Information Officer of the Robot Ethics Committee, enforcing strict human-android segregation. He is the father of Masakazu Masaki and was previously married, though divorced. This family history critically shapes his actions, particularly concerning the household android THX, called Tex by Masakazu. Discovering THX providing emotional support to his son during the divorce, Atsurou disabled its speech function, deeming such human-like interaction inappropriate—an act that seeded deep resentment toward androids in Masakazu.

Within the Ethics Committee, Atsurou actively advocates for policies restricting android integration into society. His role involves monitoring and suppressing perceived android autonomy, demonstrated by the committee's involvement in the Tokisaka Incident eight years prior, which resulted in injury to the human child Nagi. His antagonism extends to surveilling his son; learning Masakazu frequents the Time of Eve cafe—where humans and androids interact as equals—Atsurou dispatches an android agent to observe him, demonstrating his resolve to impose compliance even within his family.

Atsurou's actions consistently mirror his ideology: he views androids solely as tools and considers emotional bonds between humans and androids socially undesirable, labeling those who form them "Android-Holics." This belief drove his silencing of THX and fuels his broader efforts to restrict android behavior through the Ethics Committee. His character remains static, maintaining opposition to android autonomy throughout the narrative. This culminates when THX temporarily overrides Atsurou's command to protect Masakazu from danger, an action justified by the First Law of Robotics. His role is defined by his institutional authority, enforcement of anti-android policies, and the strained familial relationships resulting from these beliefs.