Yajisan-Kazusan is a Nikoli puzzle genre.

- Shade some cells on the grid.
- No two shaded cells may be directly adjacent.
- All unshaded cells must be connected.
- If a cell with a number in it is unshaded, the number represents how many shaded cells are in a straight line in the indicated direction.
- If a cell with a number in it is shaded, the number is meaningless, and can either be satisfied or not satisfied.