The king of the flowers in the center (of England, if you remember) has a special crystal. The king crystal.
The king thinks everyone wants his crystal so he hides it in the giant acorn (えい) in the center of the flowers in England. There's a tiny hole in the bottom of the acorn, and that's where this crystal stays hidden.
Currently there are no similar looking kanji which exist in the WaniKani learning system
Currently there are no vocabulary in our databases that utilized the kanji. Don't fret! We will have vocabulary available soon!