KEMONO JIHEN

Special detective Kohachi Inugami is sent to investigate a grisly phenomenon involving animal corpses near a remote mountain village. But after meeting a strange boy who agrees to help, he discovers cursed supernatural forces at work. Little by little, Inugami uncovers the truth behind the killings and the boy who may not even be human. (Source: Funimation) — Description from AniList community (anilist.co).