“Just one thing… Can I ask you for a favor, Masumi-san?” A yuri series about a working woman in her thirties and her high school niece begins! Masumi has always doted on her niece Satoko like a little sister. One day, Satoko confesses her feelings to her—but Masumi tries to turn her down, saying, “I’m not into girls.” However, when Satoko begs her for just one time, Masumi gives in and ends up sleeping with her. Despite it being her first lesbian experience, Masumi finds herself being brought to climax over and over again…