On the surface, high school teacher Rinko Yoshitaka treats Ryo Arase just like the other students. She regularly reprimands him for failing to complete his assignments on time and tries to keep him on track in a professional capacity. Little does anyone know, Yoshitaka and Arase steal sweet moments in each other's company. While they manage to find time for romantic escapades, Yoshitaka has one condition: the two must conceal their relationship until Arase turns the appropriate age of 20.

Despite the condition looming over them like a caution sign, Arase and Yoshitaka can barely keep their hands to themselves. But they must resist the temptation to avoid undesired attention.