OBA-101 My Sister's Private Tutor Aunt Sayuri Ikuina Sayuri

Sayuri is asked by her brother Ichiro to tutor his daughter, Haruna, who is preparing for entrance exams. However, one man is in high spirits: Haruna's brother, Shinya. That was five years ago... Shinya, who was also tutored by Sayuri, still can't forget Sayuri's intelligent profile. One day, Sayuri sees through the affection he has for his aunt. This leads to Sayuri taking an unexpected action towards Shinya...