Tenuity (Japanese sums/Pentomino chain)
(Published on 14. September 2025, 15:03 by dumediat)
This is a puzzle that I created for Piatato's birthday, and he was kind enough to suggest that I share with all of you as well.
Ratings, comments, and feedback are much appreciated! Please feel free to reach out to me on Discord if you have any comments or questions. Please also feel free to try my other puzzles here.
Rules:
- Japanese sums: Shade some cells in the grid and fill all unshaded cells with the digits 1 to 9 such that no digit repeats in any row or column. Clues outside the grid indicate the sums of the continuous segments of unshaded cells in that row or column, in the correct order. There must be at least one shaded cell separating two segments. In each row and column, either all sums are given or no sums are given. A '?' represents any digit 0 to 9, but no clue may have a leading 0.
- Pentominoes (chain): Shaded cells in the grid form pentominoes (orthogonally connected groups of 5 shaded cells). Each of the 12 unique pentomino shapes appears once on the grid, counting rotations and reflections as the same. Pentominoes may not share any edges, but they must form a single diagonally connected network.
Penpa+: https://tinyurl.com/273lbkaf
Solution code: Row 3, using pentomino letters for shaded cells and digits for unshaded cells (12 characters)
Comments
on 18. October 2025, 08:58 by KNT
Very smooth and much more straightforward than I was expecting.
on 23. September 2025, 11:04 by Playmaker6174
Very neat and cleverly constructed puzzle! The additional pentominous restriction really helped enhancing the Jsum logic and the ending was especially cute there :)
on 18. September 2025, 18:49 by MagnusJosefsson
Fantastic! So much fun throughout!
on 16. September 2025, 11:05 by Christounet
Awesome gift! Locating the pentominos was very interesting here. Thanks :)
on 15. September 2025, 14:44 by Snookerfan
Fabulous puzzle! Very original and great fun. Thank you
on 14. September 2025, 18:26 by Piatato
Thanks a lot for this great gift! I had a lot of fun solving it :D
on 14. September 2025, 16:34 by Jesper
Great puzzle, thanks!
on 14. September 2025, 16:25 by Agent
Very nice! Seems like it's not easy to find a grid that works with the twelve pentominoes, but the pentomino placement produced some cool logic until the end.
