Aim: In April and May, Professor Kiyoji Asai and Professor Hideo Tanaka, pioneers of fuzzy operational research, passed away, successively. Professor Kiyoji Asai and Professor Hideo Tanaka had worked together for more than 20 years from the 60’s on. They wrote the paper “Fuzzy Mathematical Programming” in 1974. This paper plays a pivotal role in building foundations for fuzzy mathematical programming. It is the first paper dealing with linear programming problems with fuzzy goals and constraints based on Bellman and Zadeh’s fuzzy decision-making method. In 1982, they proposed the “Fuzzy Regression Model,” which is an innovative approach to Data Analysis with potential extensions and applications. The aim is to obtain a fuzzy regression function which can cover all the data given as samples. They formulated and solved the problem by a linear programming technique. This original idea gave a new prospective direction to fuzzy data analysis and triggered of a lot of studies on extensions, generalizations and applications of fuzzy regression.