50 Samurai CalcuDokus

This book contains 50 Samurai CalcuDoku puzzles. CalcuDokus, introduced in 2004 as KenKen (a registered trademark of Nextoy LLC), is a 9x9 numeric puzzle similar to Sudoku. But, unlike Sudoku, CalcuDoku doesn't require you to learn complex strategies. A Samurai CalcuDoku is obtained by overlapping five CalcuDoku puzzles. It's a great puzzle that is fun to play, and there are no other books that let you play it.