Chōmei

, more commonly known as the, is one of the nine tailed beasts. It was last sealed within Fū from Takigakure.

Background
Chōmei first came into being in the waning days of the Sage of the Six Paths, who used his Creation of All Things ability to separate the Ten-Tails' chakra from its body and divide it into nine separate constructs that would come to be known as tailed beasts in order to ensure that it would never resurface after his death. Some time after being created, the Sage sat down with all the young tailed beasts and told them that they would always be together, even when separated, and that one day they would become one entity again with different names and forms than they did. Then, when the time came, they would know what true power is. Chōmei eventually fell into the possession of Takigakure and was sealed into Fū, but was later captured and extracted by Akatsuki.

Personality
Chōmei seems to have a happy, go-lucky personality — which it seemingly shares with its jinchūriki as shown when it introduced itself to Naruto, referring to itself as, which might be an allusion to the fact that it has seven tails and the number seven having long been seen as a lucky as well as happy number. It also had a habit of using the word lucky in conversation, reflecting its personality.

Appearance
Chōmei resembles a blue, armoured, with six of its seven tails resembling green insect wings, along with the seventh tail, all growing from the end of its abdomen. The stem of the tail is green but the wings are orange. Its eyes seem to be covered by a helmet-like skull, from inside of which, an orange glow can be seen. It also has spike protrusions on its shoulders and a row of slits on each shoulder, and six legs — three on each side. The legs are also covered by the blue armour, with the exception of extreme ends which are green in colour. It has two pincers on its face, usually covering a mouth full of sharp teeth. On its back behind its head, it has a large two sectioned horned protrusion. During the last remaining days of the Sage of the Six Paths, Chōmei was just in its larval stage of development but still had its tails.

Abilities
As a tailed beast, Chōmei possesses massive amounts of chakra that it can share with others and can use the Tailed Beast Ball. Using its wings, it has the ability to fly and can use it for insect-based attacks, such as biting or ramming its horn into the enemy. It has immense durability, able to withstand being slammed into the ground by Kurama.

Fourth Shinobi World War: Climax
After Son Gokū is resealed into the Demonic Statue of the Outer Path, Tobi, who is intent on going all-out from this point on, forces Fū to fully transform into the Seven-Tails. Preparing to attack the shinobi, Seven-Tails along with the other four beasts create Tailed Beast Balls. These attacks however, are deflected by Naruto and they are rebuffed by a now fully-transformed Naruto. After being grabbed mid-flight by Kurama, and sent plummeting to the ground and the other failed attacks by the other beasts, they prepare a collaborative Tailed Beast Ball which is met by one from Naruto and Kurama.

As Naruto enters a deeper plane of the tailed beasts' consciousness, Chōmei introduces itself to the young man. Later as the beast is freed from the chakra receiver it affirms Kurama's belief that Naruto was the person the Sage of the Six Paths had spoken about so long ago before being resealed into the Demonic Statue of the Outer Path.

Birth of the Ten-Tails' Jinchūriki
Chōmei appeared alongside the other tailed beasts with the exception of Gyūki and Shukaku when the Ten-Tails looked down at Naruto. The image of the tailed beasts, along with a silhouette of the Sage of the Six Paths, drove the Ten-Tails to a fit as it evolved further. Later, Chōmei is pulled out of Obito through the combined teamwork of the Allied Shinobi Forces, thus freeing it, alongside with the other imprisoned tailed beasts.

As Naruto in Tailed Beast Mode pinned Madara down with a tail, Chōmei and the other tailed beasts joined in and did the same to increase the damage, but the Uchiha survived their attacks and retreated to a safe distance. After he received his own right Rinnegan eye from a White Zetsu clone, Madara quickly summoned the Demonic Statue of the Outer Path from Obito's body, and used the Rinnegan to repel the tailed beasts. With the tailed beasts stunned, Madara then proceeded to chain them up and prepared to seal them back into the statue. Ultimately, Chōmei, along with the other tailed beasts, are all resealed within the Demonic Statue.

Later, the chakra Chōmei transferred to Naruto earlier manifested within Naruto's subconscious along with the other tailed beasts to speak with the young ninja and the spirit of Hagoromo Ōtsutsuki. There, they voiced their shared belief that Naruto is the child of prophecy.

Kaguya Ōtsutsuki Strikes
Ultimately, Kaguya Ōtsutsuki who had taken control of Madara was defeated by Naruto Uzumaki and Sasuke Uchiha and sealed using the Six Paths — Chibaku Tensei technique. The beasts were all ejected from the statue and then summoned back to the real world by Hagoromo and the previous Kage. After the past Kage return to the after life, the tailed beasts begin discussing their plans for the future now that they are finally free. Sasuke however makes his plans known. Desiring to kill the current Kage and seize control of the tailed beasts for his plans of revolution in the shinobi world, he quickly accomplishes the latter with his Rinnegan. With the tailed beasts subdued by his genjutsu, Sasuke then seals them away within his Chibaku Tensei. After the battle when Sasuke declared Naruto the victor, the two dispelled the Infinite Tsukuyomi and Sasuke released Chōmei along with the other tailed beasts from their prisons.

Video Games
Although Chōmei itself is not playable, Fū takes on its form as her awakening in Naruto Shippūden: Ultimate Ninja Storm 3 and Naruto Shippūden: Ultimate Ninja Storm Revolution.

Trivia

 * literally means 'Principal Brightness' or 'Principal Vidya'.
 * Chōmei is the only tailed beast to have permanently undergone a complete change in appearance, evolving from a larval stage at its creation into a more insect-like, adult form.