Specimen Raw Blue

The heart of all living things hardens and remains after the body dies. One day, a traveling merchant named Faris finds a girl collapsed in the desert and rescues her. The girl introduces herself as Eva, and Faris takes her to the oasis city of Aulof. As they walked through the town's streets, lined with villas, Eva gradually begins to trust Faris, finally telling him, "That's the house I ran away from." This is the beginning of the story of a girl carrying a "taboo."

(Source: Kodansha, translated)