The COVID-19 pandemic has heightened public awareness of infectious disease prevention. However, minors often lack fully developed hygiene awareness, making it difficult to enforce basic preventive measures such as handwashing and mask-wearing. In addition, their frequent close contact in enclosed environments, such as educational institutions, increases the risk of rapid disease transmission. As minors can serve as significant vectors of infection, understanding their movement patterns is essential for devising effective countermeasures. Despite this need, tracking minors using mobile device location data remains difficult due to the low smartphone ownership rate. Therefore, as a first step toward overcoming the limitations of mobile device tracking and enabling large-scale behavioural analysis of minors, this study developed a method for estimating their residential locations at a micro-scale, such as the building level, using various statistical datasets. Furthermore, it estimated their daily commuting destinations—such as schools and kindergartens—as well as their daily schedules and commuting routes, in order to project their routine behavioural patterns and spatial activity ranges on a nationwide scale. This approach enables a more comprehensive understanding of minors’ daily movements and supports the planning and implementation of more effective infectious disease prevention strategies.