The Key to the Kingdom (王国の鍵, Ōkoku no Kagi) is a Japanese manga series written and illustrated by Kyoko Shitou.
Unlike his brother, who participated in wars and was admired for his courage, Astarion has little interest in learning to hold the sword.
His unwillingness to succeed the throne is the cause to allow the quest for The Key to The Kingdom, a legendary item that would grant the one who finds it the right to be crowned King.
Casey Brienza from Anime News Network commends the manga for its "exquisite artwork, entertaining storyline and characters".
[8] In 2009, The Key to the Kingdom was listed as Great Graphic Novels for Teens by the Young Adult Library Services Association.