Toichika is a logic puzzle published by Nikoli. The task consists of a rectangular or square grid divided into regions. The goal is to place arrows in some cells according to the following rules:
- Each region contains exactly one arrow.
- Each two arrows are paired, they point to each other. There are no unpaired arrows.
- Two regions with paired arrows must not be horizontally or vertically adjacent.
- Between two paired arrows no other arrow must be placed.
Cross+A can solve puzzles from 3 x 3 to 30 x 30.