Sashigane is a Nikoli puzzle genre.

  • Mark edges in order to divide the grid into regions; no marked edge can “dead-end” at a vertex providing an “interior border” of a region.
  • The shape of the regions must be an “L” shape; that is, uniquely describable as having a single corner from which all other cells can be reached by going in exactly one of two directions, at a right angle.
  • If a cell is marked by a circle, it must be the corner of a region, and if the circle has a number, that number must be the number of cells in the region.
  • If a cell is marked by an arrow, it must be at a dead end of a region, and it must point towards the corner of the region.