Eiyuu-ou, Bu wo Kiwameru Tame Tenseisu: Soshite, Sekai Saikyou no Minarai Kishi♀ Mini

Synopsis

King Inglis, who lived for his country and people, strongly hopes that in his next life, "I want to further temper my skills as a knight." The wish is heard by the goddess who reincarnates the king into the far future but in the form of a cute girl! Moreover, it is declared at the age of 6 that she is incapable of being a knight despite coming from a line of knights.

Note: Mini anime series made for the Light Novel.