Sanaku is very similar to Hashiwokakero=> http://cross-plus-a.com/puzzles.htm#Hashiwokakero
The rules are the bit different though:
The goal is to connect all the islands(Circles) by drawing a series of bridges(Lines) between the islands. The bridges must follow certain criteria:
• Bridges must not cross each other.
• They may only run horizontally, vertically, or diagonally (45 degrees)
• At most one bridge connects a pair of islands.
• The number of bridges connected to each island must match the number on that island.
• The bridges must connect the islands into a single connected group.
• Some bridges are given initially, the goal is to find the remaining bridges
Note: Dotted gray lines show possible bridges, it's just to help you solve the puzzle, not a constraint
Here's a sample:
Donwload PDF version here: