Kastehelmi is set to marry the second son of a duke, Oliver, but Oliver is so infatuated with Yuriana, whom he has grown up with since childhood, that he won't even look at Kastehelmi. The duke's eldest son is also smitten with Yuriana, and on her wedding night, Kastehelmi is left alone. She realizes her predicament when she sees the duke's sons enjoying tea with Yuriana in the middle. If she tries to talk to Yuriana, she will be accused of things she hasn't done, as the duke's family dotes on Yuriana and would believe her over anyone else. Moreover, Yuriana acts like a lover or a wife to the duke's two sons, suggesting that she desires a polyandrous relationship, and the two sons seem to agree with this. Kastehelmi, who is the true wife, is left ignored. Determined to support the situation, Kastehelmi decides to back the polyandrous relationship. Now, her great counterattack begins. Also published on Kakuyomu!! Thank you for reporting typos and errors m(_ _)m