Normal sudoku rules apply. Every constraint in the puzzle is a straight line: every horizontal line is a renban, every vertical line is a German whisper, and every diagonal line is a region sum line. Different lines of the same type do not share cells. The grid is partially covered in fog. Entering correct digits may clear fog somewhere in the grid. No guessing is required. A renban line contains a set of consecutive, non-repeating digits in any order. Adjacent digits on a German whisper line must differ by at least 5. Box borders divide a region sum line into segments each of which must have the same total (different lines may have different totals).