Hitori Puzzles - 400 Puzzles 5x5 Vol.6 - David Smith - Bog

Hitori (from Japanese "Hitori ni shite kure"; literally "let me alone") is played on a grid of squares. At the beginning, each cell contains a number. The goal is to paint out some cells so that there are no duplicate numbers in any row or column, similar to the solved state of a Sudoku puzzle (except with black squares added to the grid).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.