Yukino, an elite exorcist, was ordered to exterminate the demon that has been snatching noble young ladies night after night. Shunen the demon showed up, and as soon as he saw Yukino, he promptly proposed to him, “Please marry me!” Yukino refused, but was taken away by Shunen, who has mighty power. To find a chance to counter-attack, Yukino agreed to have sex to “become husband and wife” with Shunen, but turned out Shunen is a half-demon who turns back into a human when the morning comes! Yukino most definitely can’t exterminate a human, and thus is the start of a temporary marital relationship…?!