Master of Puzzles Hitori - 200 Puzzles 25x25 vol. 6 in Bloomington, MN

Hitori is played with a grid of squares or cells, with each cell initially containing a number. The objective is to eliminate numbers by blacking out some of the squares until no row or column has more than one occurrence of a given number. Additionally, black cells cannot be adjacent, although they can be diagonal to one another. The remaining numbered cells must be all connected to each other.