This variant is pretty similar to Between 1 and 9 Sudoku, except for the fact that you aren't forced to give a given. I tried to use an opening that takes the regions into account. This puzzle shouldn't be too hard. I actually had a harder version of this puzzle, but it was a bit too much in my opinion. I didn't even have an option to make it easier without ruining most of the puzzle. I hope it's fun.
[Edit: Puzzle fixed. I made an error, forgetting 7 could be a single digit sum.]
Rules for Sudoku
In this Sudoku you have to blacken two cells in every row, column and marked 3x3 region. Then you have to place the digits 1~7 once in every row, column and marked 3x3 region. Numbers on the outside indicate the sum of the digits in between the black cells in that row or column.
|Click to enlarge|