Sayuri is hired by Ichiro as a private tutor for his daughter Haruna, who is preparing for her exams. Amid this arrangement, one man stands out, carried away by excitement—Haruna's older brother, Shinya. Five years earlier, when Sayuri had previously worked as Haruna's tutor, Shinya had fallen deeply for her intelligent demeanor. Now, one day, Sayuri sees through the affection he secretly harbors. In response, she takes an unexpected action toward Shinya. And now, this story begins to unfold.