Magi: The Labyrinth of Magic (abbreviated as Magi) is a manga with over 16 volumes that began in 2009. It's anime adaptation, ongoing with over 25 episodes, began October 2012.
Two of the three main characters are always barefoot, including:
An unnamed slave girl:
Episode in first half
A headless blue genie and a boy.
Episode in second half
Unidentified black-haired male.