Tomomi Masaoka is a former detective with the Metropolitan Police Department's Criminal Investigation Department who later serves as an Enforcer within the Public Safety Bureau's Division 01. Born in Tachikawa, Tokyo, he graduated from Hitotsubashi University's Faculty of Law with a major in Legal Studies in 2080, joining the MPD that same year and being assigned to the Detective Department by November. Initially opposing the Sibyl System for replacing human judgment, Masaoka's frustration after handling horrific cases led to a deteriorated Psycho-Pass and demotion to latent criminal status in March 2093. After time in an Adachi Rehabilitation Center, he was reassigned as an Enforcer to Division 03 in September 2093, transferring to Division 01 in May 2106. In Division 01, Masaoka acts as a mentor and father figure, particularly to Inspector Akane Tsunemori, whose views echo his own past perspective. He maintains a complex relationship with his biological son, Inspector Nobuchika Ginoza, who keeps professional distance to avoid favoritism. Despite their strained interactions, Masaoka deeply cares for Ginoza, revealing this by using his given name in conversations and frequently offering him advice, especially concerning Tsunemori. Masaoka also develops a rapport with Enforcer Shinya Kogami, bonding over martial arts and mutual concern for Ginoza. When Kogami leaves the CID, Masaoka provides access to a safe house containing a disassembled firearm and motorcycle. In February 2112, Masaoka partners with Inspector Risa Aoyanagi to investigate military pilot Teppei Sugo, suspected of terrorist activities linked to his missing commander, Itsuki Otomo. This investigation uncovers a military conspiracy involving fatal bio-weapon testing on Otomo's squad. The case reveals Otomo transferred his memories to an android for revenge, stopped by Bureau forces. These events contribute to Sugo's eventual transition to Enforcer status within the MWPSB. Masaoka dies in the line of duty in February 2113 while saving Ginoza during a confrontation. His death profoundly impacts Ginoza, who later adopts aspects of Masaoka's appearance and attitude within Division 01. Characterized by a laid-back yet reasoned approach, Masaoka maintains composure in stressful situations while relying on the Dominator. He sleeps four to five hours daily and enjoys painting, martial arts (especially judo), whiskey, and chocolate. His personal motto is "Do good deeds without expecting things in return," and he values the saying "The warrior must keep his pride even if he dies of hunger." His emergency contact is listed as Akiho Ginoza, designated as his guardian.