Naohiro Matsumura demonstrates how a powerful new design method is as simple in its logic as it is sophisticated in its psychology. It allows us to address challenges in our homes, our public spaces, and our social interactions. As Matsumura shows, a shikake-or "device" in Japanese-is a design that exerts influence on us through subtle nudging, rather than direct command; it encourages a particular behavior without telling its user the primary purpose of that behavior. Combining traditional Japanese aesthetics with the lessons of behavioral economics, Matsumura reveals how to identify the hidden design cues that already shape our world, and how shikakes can help us confront some of the most pressing challenges of our era, from pandemics to declining civic engagement to climate change and beyond. Mind-bending yet elegant, Shikake presents a tool kit for anyone who wants to create their own mindful designs, for the delight and betterment of us all.