Yuna Shiina, a covert agent with the Special Investigation Division, is deeply involved in a high-profile case classified as a national secret. Her younger brother works at a biological weapons research facility that the government has been concealing, and one day he is kidnapped by a terrorist organization. Determined to rescue him, Yuna infiltrates the enemy hideout—but is captured and taken hostage. Injected with a powerful drug developed by her brother—one that amplifies pleasure and accelerates brainwashing—she is stripped bare and humiliated before his eyes. As torture and degradation shake her mind to its core, the story unfolds into a shocking tale of familial bonds tested under extreme conditions, where the line between sister and sex slave is erased. From Aiena G's IESP label, part of the "Female Investigator: Drugged Sex Slave" series. Genres: Restraint, Aphrodisiac/Drug, Kidnapping/Confinement, Spy, Sex Slave/Cumdump.