Nanro is a Nikoli puzzle genre.

- Place a number into some cells of the grid.
- If a number is placed in a cell, that many cells in the region must have numbers placed in them.
- Every region must have at least one number placed into a cell in it.
- No 2×2 area in the grid may be entirely filled by numbers.
- The cells filled by numbers must be entirely orthogonally connected.
- Some numbers may be given to you.