Cap
かん
かんむり
None
Your forehead is the origin for the measurement for your crown! If you measure somewhere else on your head for a crown it won't fit.
You want your crown to be just like Genghis Khan's (かん), which was more of a cap. He's your hero though, because he ruled over the most people, so you want yours to match his measurements.
Currently there are no similar looking kanji which exist in the WaniKani learning system