Masahiro Irie is an emeritus professor of Kyushu University. He received his B.S. and M.S. from Kyoto University and his Ph.D. in radiation chemistry from Osaka University. In 1968 he joined the Faculty of Engineering, Hokkaido University, as a research associate and started his research in photochemistry. He was the faculty members of at Osaka University, Kyushu University and Rikkyo University. He has been conducting research on molecular photoswitch systems for more than 40 years. In the middle of the 1980s he discovered thermally irreversible and fatigue resistant photochromic diarylethenes. Prof. Irie has authored over 500 scientific publications and has received numerous scientific awards, including Porter Medal (European Photochemistry Association, The Inter-American Photochemistry Society and Asian and oseanian Photochemsitry association), Theodor-Foerster-Preis (GDCh and Deutsche Bunsen-Gesellschaft, Germany) and The Chemical Society of Japan Award.