Kaero ("Ouchihekaero"; from Japanese, literally "let's go home") is a logic puzzle created by Naoki Inaba (Japan). A rectangular or square grid is divided into regions. The aim is to move some letters horizontally or vertically, so all letters in a region must be the same. The letters cannot cross the tracks of other letters and cannot move over other letters.
Cross+A can solve puzzles from 3 x 3 to 30 x 30.