Child's Play

In Japan the puzzles (not this one) are “Samunamupure” but a UK newspaper decided adding arithmetic to Sudoku made it a “killer,” and the “Killer Sudoku” name stuck. We call them “Killer Cages” three decades later.
No cages in this puzzle, but each tiny arrow defines a “virtual cage,” so it’s a “Little Killer” puzzle. I don’t choose the names!

Rules:
Normal Sudoku rules apply.
Numbers outside the grid are the sum of all digits along the indicated diagonal. Digits may repeat if allowed by other rules.

Estimated difficulty: 2 out of 5