When azobenzene derivatives are incorporated into calamitic liquid crystalline materials, they show fascinating molecular alignment and motile functions upon light irradiation. The actions and motions are highly cooperative and thus lead to large dynamic molecular processes with obvious amplifications. The processes can be applied to photoalignment and photomotile functions in thin film systems. The research has been achieved over 30 years, but this lecture will mainly concentrate on the overview of our achievements around 15 years at Nagoya University.