We adopted an innovative methodology that combines systems thinking with “imaginary future generations” (IFGs), a method for activating “futurability” in people, to discussions about the issues and needs of a future society, and we verified the effectiveness and value of this methodology. We conducted a series of five debate experiments in which groups comprised of company employees and university students worked to formulate a vision of the future state, social issues, and social needs of society in 2050, and to investigate policies that should be adopted in the years ahead. The results of a text analysis of group debates and questionnaire surveys of debate participants showed that (1) adopting IFGs facilitates the exploration of new issues and needs when depicting the images of the future state of society; (2) adopting IFGs gives rise to recognized cognitive changes in debate participants; and (3) combining the IFG methodology with causal loop diagrams (CLDs), a systems thinking tool, makes it possible to generate the effects of systems thinking while simultaneously maintaining a “future generation” perspective. Most importantly, the results show that the IFG methodology and CLDs could be compatible. These findings demonstrate that a combination of IFGs and systems thinking can effectively be used in discussions and decision‐making that deal with complex issues related to the future of society.