Research has been ongoing on various types of soft robots in recent years. Soft robots with flexible mechanisms are expected to contribute greatly to the development of robotics, not only in industrial applications but also in various other applications, such as tasks involving robot-human interactions. Flexible mechanisms are not necessarily realized with flexible materials alone; they can also be realized by taking new approaches to conventional mechanisms. It is also desirable for sensors and various other components to be flexible so that they do not reduce the flexibility of a mechanism. The development of these mechanisms and elemental technologies will lead to the further development of soft robots. This special issue will feature papers on the structures and applications of soft mechanisms and soft elements, as well as on design and analysis methods and control techniques. We welcome many submissions so that we may contribute to the further development of soft robots.