Kuromasu is a binary determination puzzle in which the cells in a grid are split into either shaded or unshaded.


The objective is to divide the grid into shaded and unshaded cells, subject to the following rules:

  1. No numbered cell can be shaded.
  2. Numbers represent the number of unshaded cells that can be seen from that cell, including itself. A cell can be seen from another cell if they are in the same row or column, and there are no shaded cells between them in that row or column.
  3. Shaded cells must never touch horizontally or vertically.
  4. Unshaded cells must form one, connected area.


A standard 10x10 kuromasu and its solution.

Kuromasu Example
Kuromasu Answer