Eiichirou Maruo, a diligent and methodical honor student, decides to exercise more during his limited free time because he is worried about his health. Consequently, after seeing a flyer, he joins the Southern Tennis Club at the start of his freshman year. During his trial period at the club, he meets Natsu Takasaki, another first-year student who is determined to become a professional tennis player due to her love for the sport. In contrast, Eiichirou leads a study-oriented life because he believes it is what he has to do, not because he enjoys it. However, his monotonous days come to an end as he becomes increasingly fascinated by tennis the more he plays. Baby Steps is the story of a boy who leverages his hard-working and perfectionist nature to develop his own unique playing style. Gradually, Eiichirou's skills begin to improve, and he hopes to stand on equal footing with tennis' best players.