Barakamon: Mijikamon (Sub)
Watch Barakamon: Mijikamon full episodes online English Sub
Synopsis: 2-minute specials for Barakamon featuring chibi characters. These specials were streamed exclusively on YouTube only in Japan after every episode of the main series, including Mijikamon Episode 0 that was aired before the anime started airing and served as a teaser.
More info: Myanimelist, Wikipedia.