TELL ME AN ANIME WHERE THE MAIN CHARACTER IS A KING OR QUEEN

Here's what a quick google search gave me~

Shina Dark
Maoyuu Maou Yuusha
Ichiban Ushiro no Daimaou
Beelzebub
Tsubasa Chronicle
The Earl and the Fairy,
Dance in the Vampire Bund
Basara
Petite Princess Yucie
Code Geass
Slayers
Orphen
The Queen's Night

k project