Kotsuko is a word puzzle game similar to Sudoku. Players take turns placing letters in a grid. Each time a letter is used it is crossed off the list, and can't be used again. The first player to spell a word of 3 letters or more wins. Words can be spelled vertically, horizontally, diagonally, forwards, or backwards. The grids are reusable and the set comes with an erasable pen. For 2 players. Ages 6 and up.