When someone wants to view the reality of your soul, show it with humility. Because the reality is... our souls are all a little dirty. And we haven't been the best versions we could be. So make sure when you show all of yourself you do so with some humility.
As humility washes over you, you feel a shaking in your shins (しん). Humility lives in your shins, so now they're shaking and trying to bring you down to the ground.
Currently there are no similar looking kanji which exist in the WaniKani learning system