"Will you marry me to protect this hotel?" Hanakago Ayane is a 27 year old workaholic who has a 0% desire to get married. What awaited Ayane, who became unemployed due to a dispute with her boss, was a "contract marriage" proposal from Takashina, a handsome scion of a family who owns a super prestigious hotel! Moreover, his identity is a great youkai who rules the land of Sendai!? Can Ayane safely entertain the youkai guests who visit one after another by joining forces with Takashina?!