Karuji is a pure logic puzzle using a grid format and clues similar to the famous "zebra puzzle" or "Einstein puzzle". However it uses letters instead of words, and has additional clue types. The puzzles vary in size from 3x3 grids suitable for novices or kids to 5x5 puzzles. The difficulty ranges from easy up to virtually unsolvable.

As with all good logic puzzles there is only one solution.