Naka Yama is a pen name of the westerner who happens to be a fan of Japanese culture. He can spend hours learning how to succeed in Japanese calligraphy with the help of the goat hair brush and watered ink while listening to the background melodies of "shakuhachi" - weeping Japanese flute. Another time, you can watch him in awe, blending a mixture of micro elements that boost the growth of the Zen mini garden on the window sill. Anyway, most of the time, you can catch his special mysterious look while he is trying to solve a sophisticated Sudoku puzzle. And that is why he used to introduce himself as a puzzle solving enthusiast and the author of brain-training books. What he loves to do the most is to create Sudoku puzzles of different levels of difficulty. He is not afraid to call himself a "puzzles addict," and he is always keeping a hope that "Sudoku passion" will be with him for the rest of his life.