Haikyuu!! reflects Japanese high school sports culture through its focus on teamwork, perseverance, respect for opponents, and dedication to improvement. The series highlights the intense rivalries and camaraderie among high school sports teams, as well as the emphasis on hard work and discipline to achieve success in sports. Additionally, Haikyuu!! portrays the importance of mentorship from older teammates and coaches in guiding younger players, which is a common practice in Japanese high school sports culture.