Kurokuron (クロクロ一ン: "black clone"), is a shading puzzle that first appeared in Puzzle Communication Nikoli issues 153-155. Identical rules apply to a hexagonal grid.


Shade some cells such that:

  1. Bold-outlined regions contain exactly two shapes, made up of contiguous groups of 1 or more shaded cells. Within a region, the two shapes must be congruent, allowing reflection and rotation.
  2. A shape cannot share an edge with another shape.
  3. Cells with arrows, which cannot be shaded, point to a neighboring cell, which must be shaded and part of a shape consisting of the given number of cells.



Example Solution


PSE Hexagonal Kurokuron

  • 1
    $\begingroup$ Can two arrows point to the same thing? $\endgroup$ – boboquack Jun 9 '17 at 3:39
  • $\begingroup$ @boboquack yes, that is possible $\endgroup$ – paramesis Jun 9 '17 at 10:06
  • $\begingroup$ I'd like to thank you for introducing me to a new kind of puzzle! This is like some combination of two of my favorite puzzle types: sudoku and picross! $\endgroup$ – feelinferrety Jun 9 '17 at 15:05
  • $\begingroup$ @feelinferrety I hope we see more of this kind of puzzle. They're so much fun to make. I'd say it's more similar to Kurotto. $\endgroup$ – paramesis Jun 9 '17 at 17:32
  • $\begingroup$ @paramesis I hadn't heard of that one either. :3 $\endgroup$ – feelinferrety Jun 9 '17 at 18:43

Final grid

(red is shaded, gray is not shaded)

enter image description here

Explanation (Potential spoilers!)

Note that there really is one possibility to fit two regions into the 4 region (all other ways to put two 4-shapes cause them to touch). The same applies to the 6 region in the upper left corner:

enter image description here

From here, I figured out that if the puzzle were to have a unique solution, then the two shapes in the 2 region had to not touch other regions as much as possible, leading to this:

enter image description here

From here there is only one way to fill the central 7 region, and the 6 region follows easily.

enter image description here

  • 1
    $\begingroup$ Just beat me... $\endgroup$ – Wen1now Jun 9 '17 at 2:42
  • $\begingroup$ Yeah, unique solution method was easiest $\endgroup$ – Wen1now Jun 9 '17 at 2:51
  • 2
    $\begingroup$ I'm not crazy about uniqueness as a solving method. I'm glad it didn't replace critical parts of the solve path. $\endgroup$ – paramesis Jun 9 '17 at 10:10

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.