Opportunities for human beings and robots to work together are increasing. The objective of this special issuefs ten articles is to activate and expand top-quality research.

In the first, T. Muto and Y. Miyake explore interpersonal cooperative walking replicated for two human beings and the motor-control mechanisms involved.

In the second, Y. Nishikawa, Y. Kagawa, and J. Kurabayashi study control of healthcare equipment and a manipulator using electromyography (EMG) signals.

The third contribution, by T. Hashimoto, Y. Takakura, T. Hamada, T. Akazawa, and M. Yamamoto, details a walking simulator using virtual reality.

The fourth, by Y. Tang, H. A. Vu, P. Q. Le, D. Masano, O. Thet, C. Fatichah, Z. Liu, M. Yamaguchi, M. L. Tangel, F. Dong, Y. Yamazaki, and K. Hirota, proposes casual communication between humans and robots by integrating nonverbal gestures and verbal messages.

Y. Ho, T. Shibano, E. Sato-Shimokawara, and T. Yamaguchi present a system in the fifth article that uses data mining to detect human intent collecting, processing, and analyzing human motion.

In the sixth, K. Rattanyu and M. Mizukawa introduce emotion recognition based on electrocardiography (ECG) signals.

In the seventh article, K. Ogawa, S. Nishio, K. Koda, G. Balistreri, T. Watanabe, and H. Ishiguro discusses two field tests using the Telenoid android.

The eighth contribution, by H. Suzuki and H. Nishi, shows how animal gaits are implemented by quadrupedal robots.

K. Zhang, Y. Maeda, and Y. Takahashi propose multiagent reinforcement learning in the ninth article.

The closing contribution, by B. Piriyanont, N. Uchiyama, and S. Sano, proposes collision avoidance control for a quadrocopter based on the social force model concept.

We thank the referees for their comprehensive reviews and the Fuji Technology Press Ltd. staff for its encouragement and advice.