Mnemosyne: Mnemosyne no Musume-tachi

Synopsis

Twenty years after the events of episode two, Kouki is still working for Rin, and is now married to Yuki, and has a son with her. The episode opens with them receiving a call from a girl wanting to meet Rin. However, she only says one cryptic sentence and dies in front of her, which reminds Rin of a story she heard from a friend back in 1945. She soon discovers that the girl displayed the same symptoms as subjects of a biological weapon "Higan", once tested on the so-called "Death Island". The Island has been officially demolished and Tamotsu Yanagihara, a police officer and Rin's friend, confirms that its former residents were among the victims of each recent bombing in Tokyo. Soon after that, Rin is captured and brought to Death Island. Mimi decides to visit Rin's informant (whose name is never mentioned in the series) who demands sex with her in return for information on Rin's whereabouts. She informs them that the group behind the bombings and Rin's capture is called "Kudoru" (Sanskrit: Evil). Meanwhile on the Island, Rin discovers that Sayara Yamanobe survived as an immortal but has to rely on a powered exoskeleton to move. Surviving a vivisection, Rin escapes but is chased and killed again. Sayara explains her plan to exterminate humans with Higan, leaving only immortals on Earth. Kouki arrives on a helicopter to free Rin but is fatally shot. With his last strength, he consumes Shogo's time fruit and turns into an angel. After carrying Rin to safety, he returns to devour Sayara but Apos arrives to remove both their time fruits, killing them instantly. The next day, Rin and Mimi stay in their office, visibly shaken by Kouki's death.
(Source: Wikipedia)