I'm a librarian who loves anime, manga, and reading a wide variety of genres.
After seeing a recommendation for it, I downloaded this book. All 6 books in the series are free, but I'm not sure I'll be able to make it through the whole thing. The series sounds very dark, and this apparently never lets up, not even at the end of the final book.
Series description:
"Long ago the Masari and the Yata hunted together in peace, until the species they drove to extinction included those possessing nutrients necessary to Masari survival. The Yata then became the only source of those nutrients. Deviations tells how these peoples cope with the reality of being sentient creatures forced to play the roles of predator and prey, and how several of them try to thwart long-established conventions in the hope of overcoming their biological imperative. In Deviations love triumphs in the midst of death. The series focuses on the social, ethical, and spiritual dilemmas surrounding both the literal cannibalism of the societies involved and the many ways in which their different communities feed off each other."