Dr. Masataka Kawai (spelled 河合正隆) is a native of Japan and received his B.A. from The University of Tokyo (Pure and Applied Sciences 東京大学教養学部基礎科学科), and Ph.D. from Princeton University (Biology; Princeton, NJ, USA). He completed a Physiology Course at the Marine Biological Laboratory (Woods Hole, MA, USA); instructors included Andrew Szent-Györgyi, Hugh E. Huxley, Annemarie Weber, and Michael K. Reedy, who influenced Kawai to carry out muscle research. He has had postdoctoral training at Columbia University (New York City, NY, USA), where he became a junior faculty member. He is now a professor of Anatomy and Cell Biology at The University of Iowa Carver College of Medicine, Iowa City, IA, USA. He taught histology to medical and dental students (35 years), and principles of scholarly integrity to graduate and postdoctoral students (15 years). He also taught gross anatomy to medical, dental and physical therapy students since 2017. His hobbies include playing the piano, singing Japanese and Western lyrics, gardening, sky gazing, and travels. He has taken piano lessons from a concert pianist in New York City, and piano and voice lessons in Iowa City. While writing the first edition of this book, he recorded Japanese and Western lyrical songs and produced two CDs. During the second revision, he published a review on the Elementary Step That Generates Force (Kawai, 2025).