last updated: 16 Sept 2018
This the Samurai has a center X-Sudoku and 4 SudokuP (Disjoint Group)
SudokuP or Disjoint Group constraint : all digits have to be in a different position in each 3×3 box
I did not color every cell in a 3x3 box differently, because it would become to messy, and you got the picture right?
Should be easy for Pencil&Paper solving, no special methods needed.
In a picture with pencil marks: