Progress in robotics and miniaturization of computer systems has resulted in such advances as wearable robot systems that portend a new relationship between users and robots. Such wearable robots are especially important in medical and welfare use such as power assist robots that enable users to move in ways they otherwise could not. Such developments, however, bring with them new problems that require new considerations. This special issue features current advances in wearable robot systems, including papers on power assist systems, exoskeletons, wearable medical systems, and robot partners. These articles will provide invaluable references for students and researchers in wearable robots. In closing, I would like to thank the authors, contributors, and reviewers who made this special issue possible. I also would like to thank Editor-in-Chief Prof. Makoto Kaneko of Hiroshima University, for his expertise and advice in editing this issue.