Logic Masters Deutschland e.V.

Rules:

• Normal Sudoku rules apply

• Japanese sums: Shade some cells such that the clues outside the grid indicate the sums of the digits in contiguous blocks of shaded cells in the row/column. Blocks have to be separated by at least one unshaded cell.

• Twisted 159: Digits in shaded cells in column c indicate the column in which the digit c appears in that row.

  Example: if r3c3 were a shaded cell with a 6 in it, then r3c6 would be a 3

• Negative constraint: All cells that satisfy the twisted 159 rule are shaded

Link:

Penpa (Answer check enabled for entered digits, ignores shading)