Jen: Hiyoku no Tori

Overview

In this country there exists bird-men called zhen. They ingest various poisons to make themselves poisonous, and the more poisonous they are, the more brilliant their feathers become. So brilliant feathers and strong poison became points of pride for the zhen. Liuxin and Jiye are two zhen looked down upon for their unimpressive plumage, but they didn't mind as long as they had each other. Until one day, when Liuxin's attitude changed completely…!? (Source: Printemps Shuppan, translated)

Source: AniList