Kuromasu — Quick rules

Goal of the game

Choose black cells so that each numbered white cell sees exactly its stated number of white cells along its row and column, including itself.

Numbered cells always stay white. Count from each clue in the four straight directions and add the clue cell once.
Sight stops at the first black cell or the board edge. White numbered cells do not block sight; diagonals and turns do not count.
No two black cells may share a side, though diagonal contact is allowed.
All white cells must form one area connected through sides. Every cell is either white or black in the finished grid; visibility is a count of cells, not a sum of printed numbers.