In school education, it is important to encourage students to improve their social skills. Umegaki et al. (2016b) have developed an instructional model known as the Acquisition of Social Knowledge in Sport (ASKS) Model for facilitating improvement in social skills in the context of physical education. They consider that the ASKS Model with heterogeneous team organization would improve social skills that would be applicable to daily life outside of physical education classes and help students to maintain these social skills. However, no previous study has examined whether the ASKS Model would be eŠective for homogeneously organized teams. Therefore, the present study was designed to examine the type of team organization that would be most eŠective for the ASKS Model by comparing physical education classes with the ASKS Model based on homogeneous teams and heterogeneous teams. The study focused on physical education classes for male students in the second year of junior high school. The classes included those without the ASKS Model, those with the ASKS Model based on homogeneous teams, and those with the ASKS Model based on heterogeneous teams. A formative evaluation of friendship-building and the KiSS-18 questionnaire on paper were administered before and after each class. The study conˆrmed two points: First, the ASKS Model appeared to be eŠective when heterogeneous teams were organized. Second, the eŠectiveness was suggested to be improved when heterogeneity of motor skill was maintained rather than heterogeneity of social skills.