Mnemosyne

Mnemosyne (ムネモシュネの娘たち, Munemoshune no Musumetachi), also known as RIN: Daughters of Mnemosyne, is a six-episode Japanese anime television series produced by Xebec and Genco. The anime was produced to commemorate the tenth anniversary of the AT-X network, which it originally aired on. Funimation Entertainment licensed the series in North America. A light novel and a manga adaptation have also been published.

Plot
Rin Asougi runs a private investigation agency in Tokyo's Shinjuku district performing odd jobs ranging from finding lost pets to hunting rare stamps in order to get by. Yet despite attempts for a normal life, she finds herself constantly hindered by the strange cases that come her way- figures from her dark past and her inability to die.