The smartphone application business targeting students preparing for college entrance exams is buoyant amid a steady increase in smartphone users among high school students.

Naoki Miyauchi, an 18-year-old high school senior in Okayama, attends one of Japan's major preparatory schools and is studying for more than five hours a day so he can pass the competitive exam for the University of Tokyo.

He has been relying on a free smartphone application called Studyplus that allows him to connect with other users through social networking.