Rules: Divide the grid into some regions formed of adjacent squares, with using dominoes (1×2 black cells). Dominoes cannot overlap, or touch each other from the sides. Additionally, place digits from 1 to n (1-5 for the example) into the all empty cells. Digits cannot repeat in any row, column, and regions.
Background: This type is one of my design. I don’t want to say that “I invented the puzzle”. Because I just added some Sudoku rules to Dominion puzzle type. But in any case this one is a Sudoku variant, so it means that there is an idea.