Naoki Inaba has invented over 400 new types of puzzle, and also writes sudoku and other popular puzzles for magazines in Japan, where he has published several books of area mazes for children and adults.
Ryoichi Murakami is the founder and CEO of El Camino, a premier cram school in Tokyo. Many of his students go on to elite schools such as the University of Tokyo, and compete in the International Mathematical Olympiad. In addition to teaching at El Camino, Murakami is active in publishing, works as a puzzle maker, and writes questions for the Olympiad.