Princess Eder of the Zels Kingdom, born a plebeian consort daughter and mistreated by the queen and others, faces her fate when her country loses the war. As a consequence, she is forced to marry into the victorious Ostrom Kingdom — substituting her elder sister. Her fiancé is known by the nickname “Black-Wolf King” (Ortius), rumored to only be capable of fighting like a wild beast. But on the day of the wedding, Eder meets not a beast but a tall, black-haired, sharply intelligent man whose piercing eyes glint with strategy. Their encounter spirals into a struggle that will shake kingdoms and change their fates. A Cinderella-style romance filled with turmoil and transformation.