Shout out to SynVT for introducing me to the origami samurai variant.
- Samurai sudoku rules apply: normal sudoku rules apply for each 9x9 grid, boxes shared between grids conform to both grids' sudoku.
- Origami rules:
- Fold the grid in such a way that both sides are 9x9 grids and one side shows a closed blue loop while the other side shows a closed red loop. No green or pink line should show up on these folded grids. (A first fold is marked with a yellow diagonal)
- Normal sudoku rules apply on the resulting 9x9 grids as well.
- Cells folded in half to make cells of the folded grids must have the same digit when unfolded.
- Each grey box must completely overlap each other. Grey cells that match when overlapped have the same digit.
- (Note: On a printed copy, solver may have to cut a slit on the edge of one of the gray boxes in the corners to see the red loop properly.)
- Any three consecutive cells on a red line must contain digits in all three residue classes modulo 3, i.e, one digit each of the sets 147, 258 and 369. This applies to the folded red loop as well.
- Any three consecutive cells on a blue line must contain digits of all three sets 123, 456 and 789. This applies to the folded blue loop as well.
- Adjacent digits on a green line must have a difference of at least 5.
- Cells on a pink line contain a non-repeating set of consecutive numbers, in any order.
- Box borders split the grey line into connected components with the same sum.
- Digits joined by a black dot are in 1:2 ratio and digits joined by a white dot are consecutive. Not all possible dots are given.
Online in Sudokupad
***Spoiler alert***
Here are some auxiliary grids for both the blue loop and the red loop.