An Easy 9×9 Puzzle Solved with Paired Regions in 14 Steps

This 9×9 board rates as easy (difficulty score 675). Solving it from scratch takes 14 logical steps, using 6 techniques: Single cell, Row/column exclusion, Adjacency clear, Region confinement, Line confinement, Paired regions. Every step below is forced: nothing here is a guess.

1. First, every open cell left in this region sits in column A, so its marker has to land there; that clears every other open cell in the column.
2. Next, place a marker at B2. Region has exactly one open cell left. Placing here clears the rest of row 2, column B, and its region. Placing here also clears its 2 touching neighbours.
3. Then, together, two regions have open cells only in rows 8 and 9; with one marker each, those two markers have to fill exactly those two rows, so every other region's open cells there can be cleared.
4. After that, every open cell in column I belongs to the same region, so that region's marker has to be somewhere in this column; that clears every other open cell in the region.
5. Now, every open cell in column H belongs to the same region, so that region's marker has to be somewhere in this column; that clears every other open cell in the region.
6. From there, place a marker at G7. Column 7 has exactly one open cell left. Placing here clears the rest of row 7, column G, and its region. Placing here also clears its 1 touching neighbour.
7. Following that, place a marker at F1. Column 6 has exactly one open cell left. Placing here clears the rest of row 1, column F, and its region.
8. First, every open cell left in this region sits in column D, so its marker has to land there; that clears every other open cell in the column.
9. Next, place a marker at E9. Region has exactly one open cell left. Placing here clears the rest of row 9, column E, and its region.
10. Then, place a marker at A8. Region has exactly one open cell left.
11. After that, place a marker at I3. Row 3 has exactly one open cell left. Placing here clears the rest of row 3, column I, and its region. Placing here also clears its 1 touching neighbour.
12. Now, place a marker at H5. Region has exactly one open cell left. Placing here clears the rest of row 5, column H, and its region.
13. From there, place a marker at D6. Region has exactly one open cell left. Placing here clears the rest of row 6, column D, and its region.
14. Finally, place a marker at C4. Region has exactly one open cell left.

The key move here was Paired regions. Once you can spot that, this board falls quickly. ∎