Saburou Saitoh is Professor Emeritus of Gunma University with 74 years old and whose major is the theory of reproducing kernels with many applications in analysis and he published 7 books with co-authors, in particular, with Professor H. Sawano, Theory of Reproducing Kernels and Applications, Developments in Mathematics 44, Springer (2016). He published over 170 original papers. He was appointed as Emeritus Professor of Gunma University in 2009. After that, he got a five years Researcher Position at CIDMA, University of Aveiro (2009-2014). The Ph.D. thesis of Professor Saitoh had the title “The Bergman norm and the Szeg¨o norm”, and these topics held a substantial influence on his future research.