Relax and challenge your brain at the same time with kurosu, a hot new puzzle trend! The concept is so simple you'll be hooked in seconds! Also known as noughts and crosses, this puzzle has existed in some form for decades, and it has recently experienced a wave of popularity under the name kurosu. There is only one rule: No more than two Xs or Os can be next to each other in a given column or row. Kurosu promises a fresh challenge for sudoku fiends and logic lovers. With Posh Kurosu, you get a stylish and portable package that features a hidden spiral bound spine and rounded corners—making it accessible and the perfect gift for any puzzler.