Reina, formally Rena Asaoka (麻丘玲奈), is a 27-year-old office lady working in the advertising department of Best Beauty Body Inc. (BBB), a lingerie manufacturer. She possesses auburn hair, red eyes, stands 1.63 meters tall, and has a figure measuring 89-59-90. Initially presenting as part of the neutral publicity team, Reina secretly infiltrates the protagonist's department on behalf of the vice-president's corporate faction. She actively sabotages her colleagues by leaking confidential information and undermining efforts to meet critical quotas, manipulating internal leadership conflicts through corporate espionage.

Reina's loyalties shift when she betrays the vice-president's faction. This decision is driven by personal motivations, including romantic feelings for the protagonist and disillusionment with the faction's unethical activities, specifically their involvement in forced prostitution and employee exploitation. Her betrayal includes exposing compromising nude photos of herself leaked by faction members, causing significant professional fallout. Her narrative involves participation in a non-consensual sexual encounter, framed by her as self-punishment for her earlier sabotage, reflecting her internal guilt and complex relationship with accountability.

Her background reveals use as a pawn in corporate power struggles, with implications that higher-ranking executives exploited her for sexual favors to advance their agendas. This exploitation culminates in her formal designation as "the sex slave" in corporate records during the conflict's resolution. Despite her initial antagonistic role, her trajectory shifts towards seeking redemption by aiding the protagonist in exposing corporate corruption. Her ultimate fate remains ambiguous, with unresolved consequences for her former collaborators in the vice-president's faction.