This study aimed to develop a discussion model, which encourages multiple thinking, and verify its effects. In social studies, at end of each unit on “food production”, there were three rounds of pupil discussion on the issue of the problems faced by the Japanese food industry. The binary opposition approach encouraged the pupils to consider this issue from multiple perspectives. The analysis of their discussions revealed that, the process of “single reason evaluation” and “maintenance of connections and counterevidence” happened sequentially, and the discussion culminated in “consideration and integration of opinions.” It was suggested that the pupils’ multiple thinking was due to the binary opposition present in the discussion and the topic of discussion was critical in encouraging this multiple thinking.