There once was an animal with an insect friend who felt very alone unless he was around. An animal and an insect are an unlikely pairing, but these two get along delightfully and hate to be alone without the other.
One activity that the animal can never do alone is solve Sudoku (どく) puzzles. The insect always has to help him out with them, and together they are an unstoppable Sudoku solving team.
Currently there are no similar looking kanji which exist in the WaniKani learning system