Ecchan, a second-year elementary school student, fell in love with tennis because she admired her older sister, who was a coach at the Kawai Tennis Club. Although her form is a mess of what she sees, her sister's amazing tennis talent blossoms when she joins her older sister at a tennis club. However, the ninja-like female player, Kirigakure Kasumi, comes along and Ecchan is completely defeated. Later, she will have a competitive match at Kawai Tennis Club and Iga Tennis Club...? !