Ran and the Gray World(2008)

Ran to Haiiro no Sekai

Ran Uruma can't wait to grow up and become a sorceress like her mother, so with the help of a magical pair of sneakers, she transforms into an adult and sets off! Her father and older brother Jin try to keep her home safe, but Ran is determined to advance her powers and have adventures of her own!

(Source: VIZ Media)

Note: Includes six extra chapters.