In this land, there exists a bird called a Zhen. Thanks to the bird's appetite for toxic foods, poison amassed inside the bird's body changes its color, creating beautiful, vibrant wings. The strength of the poison is the pride of the Zhen. However, unaware of the danger, people became attracted to the beauty of these wings and owning the exquisite birds became a status symbol. Cai Hong, who is reputed to be the most beautiful Zhen, and General Fei, whose elder brother was killed by Cai Hong's poison, find themselves intermingled in a love-hate, animalistic Yaoi fantasy!

A Chinese general is forced to rear a poison-eating harpy, or "Zhen."

Also contains the sequel of a doujinshi titled Rekka.

Original manga:
Cmoa, Pixiv, Mechacomics, Piccoma

Official Translations:
English

Note: Polar Night is a reprint of Mangetsu no Ou, but it also contains side stories for Zhen: Tsukiyo ni Futari, Hajimete no Kanbyou-hen and a doujinshi titled Saikou.