Animating a sports series like Haikyuu!! comes with several challenges such as accurately portraying the fast-paced and dynamic movements of sports like volleyball, ensuring consistency in character designs and movements across episodes, maintaining the realism and intensity of the sports matches, and coordinating with sports experts to ensure the authenticity of the gameplay and strategies depicted in the series. Additionally, animators need to carefully balance the emotional and character-driven aspects of the story with the technical and action-packed sports sequences to engage the audience effectively.