Mauro Eytiró, better known as Ei‑chan, a diligent high school student, top of his class and simply a modest genius, at the age of fifteen finally decides that he is not entirely satisfied with his current situation and something must be done about it, namely to get physically active. After receiving a flyer from a tennis club and daring to visit the nearest one, the boy instantly becomes captivated by the bright aspirations and precise movements. Despite lacking experience and having almost zero physical preparation, Ei‑chan is determined to undertake the harsh and long journey of tennis, using his mind, abilities, and sincere devotion to the idea that has hooked him. And Mauro Eytiró joins the club.