Normal sudoku rules apply. Shade some cells such that all shaded cells are connected orthogonally by other shaded cells to the edge of the grid, and the remaining unshaded cells form one orthogonally connected area. Note that 2x2 areas that are entirely shaded or entirely unshaded are allowed. Digits in circles cannot be shaded, and represent the total number of unshaded cells seen horizontally and vertically from that cell, including itself. Shaded cells block the vision. Digits in cells separated by a white dot must have consecutive values. Additionally, one of those cells must be shaded and the other must be unshaded. Every set of orthogonally connected unshaded cells within a 3x3 Sudoku region acts as a Renban line: ie those cells must contain a nonrepeating set of consecutive digits in any order. Note that a 3x3 region may have more than one such set of cells. Also note that such a set may consist of just one cell.