Logic Masters Deutschland e.V.

Rules: Normal Sudoku rules apply. Put the digits 1 to 9 once each in each row, column and box.
Arrows: Digits on an arrow sum to the digit in that arrow's circle. Arrows do not branch, cross or share cells (including circles) with other arrows.
Circles: A digit in a circle gives how many times that digit appears in circles. Arrow circles count as circles for this rule.
Fog: The grid is partially covered in fog. Entering a correct digit in the grid will clear the fog around that digit.

Links:
SudokuPad: https://tinyurl.com/yvdtrxwt