The Perfect Insider: Azure Encounter

En route to the island, Yukihiro Yamane tells Saikawa and Nishinosono that Magata has not interacted with other people except via video conference for the 15 years since she murdered her parents. When they visit the lab, the AI named Deborah that runs the lab's physical facilities malfunctions, and an automated cart transports a wedding-dress-clad object on a cart out of the suite, which is discovered to be Magata's corpse. In a flashback to when Magata was 13 years old, she begins a sexual affair with Seiji Shindō, her uncle and director of the lab.