Aoi Rokushō

was a jōnin from Amegakure, and a missing-nin from Konohagakure.

Background
A former instructor in Konoha, he convinced Idate Morino, his former pupil, to steal the legendary lightning chakra sword called the "Sword of the Thunder God", which had once belonged to Tobirama Senju, the Second Hokage, along with a secret scroll. Idate was tricked into believing that this would grant him advancement to chūnin. Once the sword was in Aoi's hands, he fled the country with Idate, who was ashamed of his actions, and they went to Amegakure. When Ibiki Morino and two Anbu members caught up with them, Aoi had the Anbu killed, and Ibiki ended up being captured by the Ame ninja, where Aoi then tortured him to read the scroll. Idate escaped under Ibiki's advice. As Aoi attacked Ibiki, the latter escaped as well. Aoi then later managed to become a jōnin of Amegakure.

Abilities
While being recognised as a jōnin in Amegakure, Aoi's overall skill as a shinobi was average at best. Even when using a powerful sword developed by the Second Hokage, he relied too much on its power and was unable to use it to its full potential, ending up defeated at the combined efforts of Naruto Uzumaki and Sasuke Uchiha, two genin-level shinobi.

Bukijutsu
Aoi's signature technique was the Senbon Shower, a technique which allows the user to rain down senbon on their opponents through the use of hidden mechanisms concealed within umbrellas. He combined the technique with poisoned senbon, giving his opponents a slow and painful death, along with the damage done by the senbon themselves. Along with using his senbon with his umbrella, he also uses them as a regular ninja tool; not incorporating it with ninjutsu in order to preserve chakra. The bare poisoned senbon gives him an advantage, as the senbon's poison paralyses his opponents. His umbrella is also able to generate water waves capable of immobilising his opponents for a short time.

The Sword of the Thunder God, Tobirama Senju's former weapon, was also at Aoi's disposal. This sword was stolen by Idate Morino, who was tricked into giving it to Aoi. The sword has the ability to manipulate lightning, and was able to hold back the effects of a Chidori as it can cut through Chakra as if it were water. Aoi can electrify and paralyse his opponents with this sword, and make trails in front of him, to shield him from frontal attacks. Every time it is moved, it makes light sabre-like noises. The sword does have a weak-point, as the blade can be cracked with repeated use in battle, and soon shattered.

Land of Tea Escort Mission
Aoi and Team Oboro were hired by Kyūroku Wagarashi of the Wagarashi Family to prevent Idate from winning the Todoroki Shrine race, and to make sure that Fukusuke Hikyakuya won the race. If Idate had lost, Jirōchō Wasabi and the Wasabi family wouldn't have controlled the Land of Tea any longer. Aoi ambushed messengers going to Konoha with a letter requesting help, easily defeating them. Despite this, the messengers managed to take the letter to Konoha.

Team Oboro then met up with Aoi, asking for instructions. He ordered them to follow Idate, while Aoi went to Fukusuke. Later, Aoi and Fukusuke were on a ship, observing Idate run away. Aoi claimed that he has always been like that, surprising Fukusuke about Aoi knowing Idate. Soon, after Team Oboro destroyed Idate's ship, Idate was told to swim away from it. As soon as Idate got to a rocky island, Aoi walked up to him, surprising Idate about Aoi's appearance.

Aoi then injured Idate's arm. He then threw his umbrella up, stabbing Idate with many poisoned senbon. Eventually, Naruto Uzumaki, Sakura Haruno, and Sasuke Uchiha finally arrived to Idate's rescue. Aoi arrogantly claimed that no matter how many genin were teamed up against a jōnin, the odds of the jōnin wining won't change. He then dodged many frontal attacks coming from Naruto and Sasuke, jumped up in the air, and used his Senbon Shower technique on Team 7, although they managed to survive.

Later in the race, Fukusuke told Aoi not to botch up the mission. Aoi grabbed Fukusuke telling him that if he threatens him again, he will break him. Before Idate can catch up to to Fukusuke, Aoi ended up ambushing Idate with the Sword of the Thunder God and cut one of the ropes to the bridge. Aoi fought Naruto and Sasuke again. Idate tried to help, but kept on getting electrified by Aoi. Sasuke used Chidori to make a crack on the sword, before being electrified, and nearly killed by Aoi, as he was thrown head-first down a cliff. Sasuke was saved by Sakura. Naruto then fought Aoi, and defeated him with the Rasengan; by aiming at the crack on the sword, Naruto was able to break it. Once the Rasengan hit Aoi, it sent him flying off the cliff where he fell headfirst into the water. Seeing as he said that a fall from that height was fatal, Aoi died from the fall.

Trivia

 * means blue, and means copper rust.
 * Despite being an anime-only character, Aoi's impact on deriding Sasuke Uchiha served as added incentive for the latter to defect from Konoha, though Sasuke's loss against Gaara and Naruto's accelerated improvement were already enough in the manga. Likewise, in the anime, he is responsible for the large scar across Ibiki Morino's face.
 * Out of all the known ranked Amegakure shinobi, Aoi is the only one which isn't a genin.