You take a stool, another stool, and yet another stool and stack them on top of a tree to make a mulberry bush. This is how mulberry bushes are made. You take three stools and you put them atop a tree.
You then eat a mulberry because a mulberry will cure (くわ) any and all ailments. A mulberry is the cure-all of nature.
Currently there are no similar looking kanji which exist in the WaniKani learning system