In a rice paddy you find a heart and it makes you think. You think a lot of things like, "Whose heart is this? Why is it in a rice paddy? Why am I thinking out loud?"
You think this heart is from a sheep (し). It's big and covered in wool. It's also baa-ing a little. Why would you think anything else?
Currently there are no similar looking kanji which exist in the WaniKani learning system