Goishi Hiroi, also known as Hiroimono, is a binary-determination logic puzzle.
Goishi Hiroi is played on a rectangular grid in which circles appear at some of the intersections on the grid.
The object is to conceptually claim the circles from the grid, as though they were stones on a board. Starting with a stone, continue in any orthogonal direction until an unclaimed stone is reached. Repeat until all stones are claimed. Once a solution is found, number the stones in the order required to claim them all. You may not skip over unclaimed stones, although you may skip over empty spaces or claimed stones.