Play Kakurasu Online — Free
Shade cells in a grid. Each row and column has a target sum, and the value of a shaded cell equals its column (or row) position number.
Choose a puzzle
About Kakurasu
Kakurasu is a beautifully elegant shading puzzle. You shade cells in a grid according to positional values: a shaded cell in column C contributes C points to its row’s total, and a shaded cell in row R contributes R points to its column’s total. Row clues give the required row totals; column clues give the required column totals.
This positional-value mechanic makes Kakurasu feel quite different from other grid-shading puzzles. Shading a cell in column 5 has a much larger impact on its row’s total than shading a cell in column 1. You’re solving a system of weighted constraints, not just counting.
Kakurasu is less widely known than Nurikabe or Nonograms, but it has a dedicated following who appreciate its mathematical elegance. The combination of shading decisions and positional arithmetic creates a satisfying tension that’s hard to find elsewhere.
Start with clue 0 lines — every cell in that row or column must be empty. Then look for lines where the clue equals the sum of all indices, forcing every cell to be shaded. These anchors dramatically narrow the solution space.
Frequently asked questions
What is Kakurasu?
Kakurasu is a grid puzzle where you shade cells. The value of a shaded cell equals its position (column 1 = 1, column 2 = 2, etc.). Each row and column has a target sum that your shaded cells must match.