The Research Core "New Chemical Materials for Actuating and Transmitting Mechanisms" invited Dr. Nagatoshi Koumura for his lecture on "Discovery of molecular rotors that can be driven by photo-energy and Elucidation of the mechanisms". He had been a coworker of Professor Feringa, who won the Nobel Prize in Chemistry 2016 for their design and production of molecular machines. The clear, beautiful, and informative lecture fascinated us and stimulated our imagination so much.