You're in prison, but you can use your fingers and a spoon in the light of the sun to display little moving pictures on your cell wall. It's like a shadow puppet display except you can only make a few characters with your limited hand tools.
There is one thing you display more than anything else and it's cake (けい). You smush your fingers to make a cake shape and use the spoon to pretend you're eating it.
Currently there are no similar looking kanji which exist in the WaniKani learning system