Logic Masters Deutschland e.V.

My second mini killers puzzle, since my first one was well received. :)
It should have a similar level of difficulty.

RULES:
- Standard sudoku rules apply.
- The small arrows act like little killer clues for the box they are pointing at. The sum of the digits in the direction of the arrow in the box pointed at equals the digit in the cell with the arrow.
- The grid is toroidal, meaning that the top side is connected with the bottom side and the right side is connected to the left side. E.g., the arrow in R9C3 is pointing at box 2.

Here's a 4x4 grid example:



And this is the puzzle:



Enjoy!

Link to solve it online:
Penpa+