Hoshikage

The Hoshikage (星影, Star Shadow) is an anime only Kage from the small Hoshigakure. The Third Hoshikage was killed by Akahoshi, and he became the Fourth Hoshikage for a short time. After the people of Hoshigakure discovered he killed the Third Hoshikage, he was defeated by Naruto Uzumaki and given to the proper authorities. His fate and the next Hoshikage are unknown.

The Hoshikage is not a true 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 recognized as an actual Kage. The title is, in all likelihood, 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. It is the long-standing goal of the Hoshigakure to achieve sufficient power to have their Kage recognized as such.

First Hoshikage
The First Hoshikage (Shodai Hoshikage; Literally meaning "First or Founding Star Shadow") was the founder of Hoshigakure. Two hundred years before the start of the series, he found a "fallen star" (a meteor) with mystical powers. Once he discovered this, he founded the Land of Bears, in hopes to make well-renowned shinobi and gain the title of a great hidden village. Unfortunately, he didn't know of the side effects of the star training, and people started to die from overpowering chakra that imploded in their bodies.

Third Hoshikage
The Third Hoshikage (三代目星影, Sandaime Hoshikage; Literally meaning "Third Star Shadow") was the former leader of the Hoshigakure. His real name is unknown. He banished Sumaru's parents from stealing the star, but also completed their wishes by banning the Star Training from continuing. He was murdered by Akahoshi.

Fourth Hoshikage
There was never an official 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.