A couple's happy life starts from a political marriage.
Raphie is a princess of the demon clan feared as the "Poison Princess" because of the poison she spreads on the battlefield. Loren is an "Undying Knight" who can revive himself repeatedly and return to the front lines to continue fighting.
As a sign of peace, the two become husband and wife in a political marriage full of mixed feelings, but Loren falls in love with Raphie at first sight and wants to flirt.