Unable to tolerate her brother-in-law's habit of cheating, Riho, the elder sister of the wife, comes to stay at our home. Although the brother-in-law claims he provides living expenses, his wife feels embarrassed by Riho's presence and issues a "no sex rule." As a newlywed, I am forced to endure this abstinence, making daily life increasingly difficult. Riho moves around the house every day in revealing, carefree outfits, constantly testing my self-control. After a month, I begin to reach my limit, overwhelmed by the bold allure of my sister-in-law.