Cozy logic mystery for iPhone
Murder sudoku.
With suspects.
Put every suspect in their place, cross clues that never lie, and discover who committed a very small — and very silly — crime.
- Easy cases free
- No ads
- No subscription
60handmade cases
3suspicious worlds
1fresh daily case
∞bad excuses
How to solve a tiny crime
Think sudoku.
Then add a punchline.
Every case is a self-contained logic puzzle. There is one suspect per row, column and zone — and exactly one solution.
- 01
Read the scene
Someone stole a lunch, swapped the coffee, or committed another deeply unserious offense.
- 02
Cross the clues
Place suspects and mark impossibilities. Every clue is true; the board does the rest.
- 03
Catch the culprit
Complete the grid, reveal what really happened, and enjoy an alibi that should fool nobody.
Actual cases. Actual questionable behavior.
Your next mystery is already making excuses.
Three worlds, sixty cases
Crime has never been this inconvenient.
Start with free cases in every world. Unlock the complete collection once — no subscription, no ads — and new cases can arrive without an app update.
Open the first case- 01
The Office
Missing lunches, suspicious meetings, and stationery with a criminal record.
- 02
Tea & Tiny Crimes
A cozy village where the tea is warm and everybody knows too much.
- 03
The Grand Hotel
Polished floors, impeccable service, and alibis left at reception.
No detective degree required
Learn by solving, not by reading a manual.
An interactive first case teaches rows, columns, zones, notes and clues as you use them. Start on very easy; end up arguing with expert suspects.
- Five difficulty levels
- Hints that preserve the deduction
- A unique solution in every case
Doña Lupa's case notes
Learn the rules.
Keep the mystery.
Clear, practical guides for reading the board, crossing clues and solving suspect-filled logic puzzles without guessing.
How to play deduction sudoku
Rows, columns, zones and the exact solving order for your first case.
Open the case file → Solving methodDetective logic grids
A five-pass loop for turning story clues into forced placements.
Open the notebook → Genre guideFair mystery puzzles
Why one answer, honest evidence and a closed cast make deduction satisfying.
Inspect the evidence →The interrogation room
Questions with
straight answers.
Is Doña Lupa really sudoku?
It uses sudoku's one-per-row, one-per-column and one-per-zone rule, but replaces numbers with illustrated suspects and adds truthful story clues. You never need to calculate anything.
Learn how deduction sudoku works →Do I need to know number sudoku first?
No. The interactive first case teaches rows, columns, zones, notes and clues as you use them.
Read the beginner guide →What are the basic deduction sudoku rules?
Place every suspect once in each row, column and outlined zone. Combine those constraints with the case clues until every cell is determined.
See the rules step by step →Are all the clues true?
Yes. Every clue in a Doña Lupa case is true, so a contradiction means an earlier placement needs another look.
Learn how to cross clues →Do I have to guess when I get stuck?
No. Keep both candidates open, inspect their intersecting row, column and zone, and return to clues that gained meaning after your last placement.
Use the no-guessing method →Are the mysteries scary or violent?
No. The cases are cozy comic mysteries about missing lunches, suspicious coffee and other very small crimes.
Explore cozy logic mysteries →Does every case have one solution?
Yes. The clues and board constraints are designed to lead to one checkable final arrangement.
See what makes a puzzle fair →Can I play Doña Lupa for free?
Yes. Easy cases are free in all three worlds, including a fresh daily case. One optional purchase unlocks the full collection; there are no ads or subscriptions.
Meet your first free case →