Star Guard Mission

The Hoshigakure Arc spans from episodes 178 to 183 of the Naruto anime.

Summuray
While having a snack with Sakura, Naruto learns that Neji, Lee, and Tenten were sent on a mission to aid Hoshigakure protect their precious chakra-emitting star (which was actually a meteorite) from thieves. Suspecting that Orochimaru might be behind these attempted thefts, Naruto convinced Tsunade to add him to the team. After Naruto and the team arrived at the base of the Hoshigakure, they met a young Hoshi genin named Sumaru who escorted them safely around the deadly gases surrounding the village. They were then introduced to the acting leader, or "Hoshikage" of the village Akahoshi who explained the situation. It was revealed that the special star enhances the chakra of whoever trains under it long enough and enables them to manipulate their raw chakra in very unique ways, forming a ninjutsu known as the Mysterious Peacock Method. Later, the star was stolen by a masked ninja who possessed the same star-enhanced techniques as the Hoshigakure only more powerful and refined.

While Naruto began making friends with several of the Hoshi genin, he learned that Sumaru lost his parents when he was young and dreams of becoming Kage of his village. Later after Sumaru was kidnapped by Akahoshi (disguised as the masked ninja), it was discovered the real reason why the star was so coveted by other villages was because of the dangers to using it as very few in history have survived the star-training. The forced releasing and enhancement of chakra generally proves too unnatural for most people to adapt to, causing the body to give out and die before it can properly synchronize with the chakra. And even if a person does complete the training, there is still a chance the person will eventually be killed by the enhanced chakra. Although the Third Hoshikage who died recently, stopped the training, Akahoshi resumed it soon afterwards, which the Hoshi ninja have been willing go through for the village's prosperity.

Later, Naruto found himself up against the masked ninja again when Akahoshi attacked with the intent of killing the masked ninja and knocked Naruto and the masked ninja into the poisonous cavern. Fortunately, the masked ninja saved them both. Naruto then discovered that the masked ninja was actually a Hoshi jōnin named Natsuhi, who was Sumaru's mother and one of the few people to ever successfully complete the star training. She explained that ten years ago, despite Natsuhi and her husband, who sometime later died, convinced the Third Hoshikage to stop the star training in exchange for faking their death and watching over the village from a far. After hearing how dangerous the star really was, Naruto was determined to help Natsuhi stop Akahoshi, who was deliberately using the Hoshigakure for his own selfish goals. Upon facing off with Akahoshi, he revealed to have killed the Third Hoshikage so he could take over the village and resume the star training and willing to sacrifice anyone as long as the village got the glory he desired. After Sumaru appeared, Akahoshi used him as a hostage to force Natsuhi to give him the star.

Despite Naruto's anger at Akahoshi, Neji reminded Naruto that technically, Akahoshi is not a villain to the Hoshigakure as they all wish to make their village strong as well and as such, the Konoha ninja cannot do anything against the village leader without repercussions. Later, Natsuhi attempted to retrieve the star again despite her failing health, but was killed by Akahoshi. It wasn't until one of the Hoshi genin showed the villagers the damage the star training did to his body and the truth of the Third Hoshikage's death were revealed that the villagers finally turned against Akahoshi. Deciding to regain control by any means, Akahoshi embedded the star into his being to gain a tremendous power increase. With the help of a final techinque left behind from Natsuhi, Naruto was able to defeat Akahoshi and destroy the star using the Rasengan. Later, the infected Hoshi ninja were taken to Konoha for treatment from Tsunade and are cured. Naruto is glad to see that despite losing the star, the Hoshigakure still is determined to become recognised as the next Great Shinobi Village.

Episodes