Middle-schooler Mayuki wants to enter Ohtomo high school to join her beloved senpai Akira. Problem is: her grades are so terrible there's no way she can make it into such a high level school. Her mother then hires a high school girl named Rin as a private teacher to help her daughter. Seeing how the girl looks so much more mature than her, Mayuki ends up asking Rin to teach her more than just school subjects… (Source: Kadokawa, translated)