Hoshikage

Hoshikage (Star Shadow) is an anime only Kage from the small Hoshigakure. The Third Hoshikage was killed by Akahoshi, and he became the Fourth Hoshikage by a short time. After the people of Hoshigakure discovered he killed the Third Hoshikage, he was defeated by Naruto Uzumaki and given to justice. His destiny and the next Hoshikage are unknown, but Akahoshi probably was put in jail or killed.

Please note that the Hoshikage is not a legit kage, as both the anime and the manga clearly point out at one point or another that there are only five kage, ruling the five major countries. The Hoshikage is not on the list, and therefore is not regognized as an actual kage. The title is, in all likelyhood, simply a formality. The five mentioned kage are the Tsuchikage of Iwagakure, the Mizukage of Kirigakure, the Hokage of Konohagakure, the Raikage of Kumogakure and the Kazekage of Sunagakure.

The First Hoshikage
He lived about 200 years ago, when the "star" crashed near the Hidden Star Village. He began the star training, but he never knew about the side effects of the training.

The Second Hoshikage
There is nothing known about this Hoshikage.

The Third Hoshikage
He stopped the star training because of the star training's side effects. He was eventually killed by Akahoshi, who took over the village and started the star training once again.

The Fourth Hoshikage
There was never decided a Fourth Hoshikage. Akahoshi claimed to be the Fourth, but was never given the title. Sumaru wanted that title as much as Naruto wants to become Hokage.