Masahiko Nomi (1925-1981) was a Japanese author, thinker, and pioneer who devoted more than 30 years to studying the connection between blood type and human nature. After graduating from the University of Tokyo with a degree in electrical engineering and later studying political science at the same university (which he left before completing), he worked as a textbook editor, broadcast writer, magazine and encyclopedia editor, and publishing executive. In the early 1970s, he became a full-time freelance writer, publishing widely on blood types and other subjects. Nomi's findings revealed fundamental connections between the ABO blood types (O, A, B, and AB) and patterns of perception, emotion, thinking style, and behavior. He named this new field of study blood type humanics. Between 1971 and 1981, Nomi published 12 best-selling books on the subject, sparking a revolution in how people understand themselves and others. His work reshaped public consciousness in Japan and later gained wide readership across Asia, including China and South Korea, where his books were translated and went on to become highly influential. Nomi's work is seen by many as groundbreaking. His research offers real world, evidence-based insights that challenge long-held assumptions in fields that study human nature, including psychology. Because of its impact and potential to reshape how we understand human nature, Nomi's breakthrough has been compared to those of great thinkers such as Newton and Einstein-except this time, the subject is not the outside world, but human beings themselves. In addition to his research on blood type, Nomi had wide-ranging interests and published seven other books on topics such as sumo wrestling, Japanese history, and rakugo; he regularly contributed to sumo magazines and was considered a first-class commentator on the sport. Nomi passed away suddenly in 1981-at the age of 56-while delivering a lecture on blood type humanics. His blood type was B.