Guest-edited by Naoto Chatani and Jin-Quan Yu, this Special Issue was published at the right time, as the 4th International Symposium on C−H Activation (ISCHA4) will be held in Yokohama, Japan, this August. It aims to serve as a source of stimulation for further developments of a research field that originated in Asia. Explore the latest findings and enjoy free access until November 30, 2018.