The most fun thing about these little arrows is how many cells they affect. All of these arrows form 5-cell or 7-cell virtual cages, more or less. These things are so long that even though they’re on opposite sides of the puzzle, they still have cells in common! Every single line arrow overlaps with at least two other arrows, believe it or not.
I still don’t love some of the names of these variant constraints. “Little Killer” clues sit outside the grid and affect diagonal swathes of digits, but in this grid, I’ve kept a large area free of any influence, and colored it mint green. Which means that area is free from any clues, too. And yet the puzzle can be solved with just a bit of arithmetic.
It is admittedly harder to explain how Sudoku doesn’t actually have anything to do with arithmetic when there are variants like this one which do. And this one has a lot of arithmetic.
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!