Sudoku

Sudoku is a logic puzzle created by some american. Maki Kaji (otherwise known as the Godfather of Sudoku) was the person responsible for bringing Sudoku to the world. He set up the puzzle company nikoli and set up refining Sudoku. First he made the starter digits appealing, with symmetry. Then he asked the rest of nikoli to make hand-made puzzles. The only book at the moment with nikoli's hand-made Sudoku is Puzzler Sudoku. Now, Sudoku is a major puzzle which has variants of its own. There are about 300 (or probably more) sudoku websites to play it on. The rules are not to hard to understand: Place the digits from 1-9 in each row, column and 3x3 box only once. Moreover, Sudoku appears in The Times, The Guardian and many more newspapers!