Rin: Daughters of Mnemosyne

Rin Asougi, a private investigator, has been alive for centuries due to her immortality. Although this ability would be desirable to many, it also makes her a target for those who want her dead. Rin has died numerous times over the years, but each time she returns to life.

She meets Kouki Maeno in 1990, who believes his memories are false. When Rin agrees to help him, she discovers that Kouki is not what he appears to be, and she becomes closer to her true enemy, who is well-informed about Rin and her kind. This adversary's goal is to kill her and potentially end her immortality permanently.