In this article, we discuss how sustainable development can be enabled in healthcare through the playful use of children's buildingblocks and storytelling, which we subsume as art-based mediation. In recent years, health care systems in most countries have been confronted with the problem of having to balance tensions between quality of service and costs. Therefore the development of processes, technologies and products can be seen as fundamental for the sustainable development of health care systems as a whole. This study is based on empirical research carried out with health care professionals in Osaka, Japan, who were tasked to develop future visions for a regional health care system. The interdisciplinary participant groups require a holistic approach to sustainable development, which includes economic, environmental and social dimensions. The findings show that playful modeling with toolkits and storytelling provides a method to deal with the different dimensions of sustainable development and the participants’ perspectives. We conclude that this form of art-based mediation complies with two essential demands to successfully initialize a multidimensional sustainable development process: a) the sharing of different understandings among participants, b) the development and sharing of creative ideas regarding sustainable development. We see the contribution of our research as a conceptual combination of art-based mediation with sustainable development in an interdisciplinary context. The scientific benefit of the article lies in the theoretical exploration of how sustainable development can be connected to art-based intervention. Based on this empirical research on health care system development, it can be demonstrated how a playful modeling process leads to a shared understanding and development of ideas regarding sustainable development of health care systems.