Mochikoro (" Mochinuri ") is a logic puzzle. It consists of a grid, with numbers in some cells. The aim is to blacken some cells of a grid according to the following rules: - The black cells divide the grid in rectangular areas ("islands") of white cells. - No two islands may share an edge, but all of the islands must be connected to each other through their corners. - Each numbered cell must be a part of a white island. Some white areas may not include a cell with a number. - Each island must have the same number of white cells as the number it contains (including the numbered cell). - No 2 x 2 cell area within the grid can contain all black cells.