This study demonstrated that a school-based smart health care service can effectively support adolescent health management by integrating personalized health data, gamification, and interactive tools. The usability evaluation revealed that students and parents prioritized sleep and physical activity tracking, while school health teachers emphasized the importance of monitoring physical activity. In addition, reward-based engagement strategies were identified as a promising approach to improve adolescent health behaviors. These findings suggest that leveraging digital health solutions tailored to adolescents' needs can contribute to establishing sustainable health habits from an early age.