Hotaru Beam Description
Hotaru Beam is a puzzle originally from nikoli; their description is only in Japanese, but Wikipedia has a decent article. A number of circles with dots and possibly numbers appear. From each circle, a “beam” must be drawn from the dot along the grid lines, eventually terminating at a different circle.* When all beams are drawn, all the circles will be connected in a single network. If there is a number in the circle, that number tells how many right-angled turns the beam makes. A beam cannot intersect itself or any other beams, even at a corner. The solution is unique.
Below is an example puzzle and its only solution. (Beams are indicated by dark, thick lines.)
* Given the fact that I cannot read Japanese and the relatively limited information on this puzzle available to me, I am not certain whether nikoli’s puzzles allow beams to hit the circle that fired them or not. In any puzzles posted here, this will not be allowed.