Alkaloid no Hanayome  

Alkaloid Bride, アルカロイドの花嫁

A story of a contract marriage between an immortal man and a lonely girl.Romelia, a lonely young woman, and Kutli, a high-ranked military officer, are solemnly married in the name of God. What they share, however, is not "conjugal love," but the burden of an "unbearable fate."(Source: Comic Days, translated)