Ao Arc

The, also known as the in the anime, is an arc of the Boruto: Naruto Next Generations series. It spans from volumes 5 to 6, and covers chapters 16 to 23 and episode 178 to 187. In the manga, it is preceded by the Mujina Bandits Arc. In the anime, it is preceded by the Kara Actuation Arc. In both medias, is followed by the Kawaki Arc.

Threat of Kara
As the Inners of Kara are summoned to a meeting by Jigen, he informs the members that the vessel has been lost. As two members voice their frustration, Victor reassures them everything will be fine. Jigen informs Victor that Amado is absent due to being reassigned to another mission. He mentions that while their group accounted for a loss in time, the event was a preventable human error. As Victor suggests they should mobilise an Outer to collect data on the new Scientific Ninja Tool, Koji voices his desire to handle the situation himself, which the group allows him to do. Concluding the meeting, Jigen ends the genjutsu. Afterwards, Victor curses Koji and the members that mocked him, leading to Koji revealing himself to the man, and explaining he was present with him before the meeting started. Preparing to attack Koji, he is struct by a kunai and set ablaze. Overcoming the Victor's regeneration jutsu, he dies, leading Koji noting that he's linked to Konohagakure.

In Konoha's Training Hall, shinobi watch Boruto and Naruto fight. Using shadow clones to distract his father, Boruto throws his Rasengan at Naruto, which vanishes before him. Not sure how his father countered his technique, Boruto attacks with lightning-infused waves, which Naruto blocks with his Earth Release wall. Impaling the wall with his hand, he absorbs the techniques with hand. Noticing the hand is still situated in the wall, Naruto appears behind Boruto, and swifts kick the genin, prompting Shikamaru to end the duel. Looking over at Naruto, Boruto notices his father is missing his right hand with it still in the wall, followed by Naruto telling Boruto he's got stronger.

At the Hokage office, Boruto is informed Naruto's hand was a Scientific Ninja Tool, which outrages him. Naruto explains he instructed Katasuke to make the tool after getting the idea from the battle against the Ōtsutsuki clan, and goes onto explaining its mechanics. Still outraged by Naruto, Sasuke arrives, and tells his student that the tool itself isn't wrong, but the key is how you use it. Naruto assigns Team 7 a mission to escort Katasuke and the prosthetic to another lab. On the Land of Fire border, Konohamaru and Mugino investigate a crashed blimp. Discovering a container inside it, something approaches them in the distance.

At Kara's base, Amado performs maintenance on Jigen, while sharing concerns on uncovering the traitor from the blimp crash. Jigen shares the suspicion that although Victor did attempt to steal the vessel, the crash happened through a different reason. He also reaffirms that it was not done by Victor as he felt the vessel being moved via the Kāma. Amado later takes Jigen's suspicions as an order to investigate the other Inners.

As Team 7 and Katasuke take the Thunder train for their mission, they encounter Ao. Katasuke introduces Ao as one of his patients. When Boruto shares his disdain for scientific ninja tools, Sarada notes that current games and technologies are due to scientific innovations. While Katasuke performs maintenance on Ao's arm, Boruto learns that Ao was a former shinobi from Kiri, and that he is alive due to the innovations of scientific ninja tools. Upon noticing that Boruto is lukewarm on the idea of those tools, Ao grabs the screwdriver from Katasuki and nearly stabs Boruto, noting that the tool is not necessarily good or bad, but rather how it is used. Upon Team 7 and Katasuke departing the train, Ao encounters Koji and learns that Victor is dead. Koji praises Ao's ability to place Katasuke under a genjutsu to extract information on scientific ninja tools and assigns him a new mission to retrieve the missing vessel from the blimp crash and kill anyone who has interacted with it.

A New Mission
At Kara's base, Amado reveals to Code and Delta of Victor's treachery and death. In the meantime, Team 7 and Katasuke arrive at the research facility, where they are greeted by Akita Inuzuka, Nue, and Sumire. As Akita shares excitement over testing Katasuke's prototype, Boruto remains unconvinced of the value of scientific ninja tools. In the lab, Team 7 undergo a series of tests using scientific ninja tools— some of which Boruto had fun with. While Sumire tends to Boruto's injury from testing, Sumire expresses interest in developing a tool to help control Nue in order to support the village. Boruto befriends Akita's ninken, Chamaru, and notices that he has a prosthetic leg. While Boruto notices Katasuke's goals in helping others using science and technology, Katasuke shares a prototype chakra blade with him, noting that high chakra expenditure from wielding the weapon can tire him out. Naruto later contacts Team 7 on the lab and notes that he has lost contact with Konohamaru and Mugino, and issues them a new mission to check over them.

While preparing to leave the facility, Chamaru and Katasuke join Team 7 on the mission, with the latter trying on a new prototype mechanical suit used for combat. Arriving at the airship crash site, Team 7 notices several scattered puppets. While the group investigates the area for a potential puppet user and the airship, the scattered puppets activate and attack Team 7, constantly getting up and firing after retaliation. Katasuke steps forward and creates an absorption sphere using his prototype arm to absorb all the attacks to the point where the puppets overheat and temporarily shut down from continuous firing. While instructing Team 7 to destroy the puppet's power supplies, Katasuke shares guilt upon learning by Ibiki that he may have leaked intel while under a genjutsu.

Ao's Assault
In a cave, Konohamaru tends to Mugino's injuries. Team 7 finds them, and they catch each other up on what happened. While Konohamaru attempts to let Katasuke analyse the data acquired, they are interrupted by Ao. Ao points a weapon at the group and asks about the contents of the container. Konohamaru refuses to share intel from a mission, so Ao opens fire against them. After Katasuke absorbs the attacks with Konohamaru breaking Ao's weapon, Konohamaru asks about the container and Kara. Knowing of the team's intel on Kara, Ao attacks the group, only to be stopped by Mugino. As Mugino holds on to Ao and instructs the group to leave, Ao pierces Mugino with a hidden tool in his arm. As Mugino collapses the cave while holding onto Ao, the remainder of the team escape. Ao breaks free from the rubble, and vows to kill them all.

While hiding in an abandoned structure, Sarada tends to Konohamaru's wounds. Mitsuki notes that Ao isn't pursuing them at the moment. Boruto remains frustrated with Mugino's death and intent of his sacrifice. They discuss Ao's alignment with Kara and discuss tactics to defeat him. As they discuss potential decoys, Katasuke again shares guilt on leaking intel as well as feeling responsible for Ao's misuse of his technology. Boruto confesses he used to agree that scientific ninja tools shouldn't exist, but seeing their positive influence in his lab changed his mind. They devise a plan using scientific ninja tools in order to defeat Ao. In the meantime at Kara's base, Amado shares knowledge of his investigation while Code and Delta point out that maintenance has not been performed on Boro or Koji, wondering where the latter is. As Ao begins searching for the escapees, Koji appears before him, questioning Ao of his commitment and loyalty towards Kara.

As the Konoha shinobi prepare for Ao's attack, they discuss his prowess and the plan to defeat him. Ao notices where they are hiding, and attacks Mitsuki, whose Lightning Release counterattack Ao absorbs. As Konohamaru attacks Ao with Fire Release, Ao deduces that they are not conserving chakra and have a strategy against him. The three continue attacking with ninjutsu for him to absorb and dodge. Ao creates a greater absorption sphere to absorb all their attacks at once. Ao notes Boruto's absence, and determines him to be vital to their strategy. Boruto strikes from above with the chakra blade, which Ao blocks with his own. Ao grabs Boruto's chakra blade and stabs him with it, only to reveal that it was a shadow clone. Mitsuki wraps his arm around Ao's arm to bind him and let the blade drain his chakra. The real Boruto attacks with a Rasengan, and uses the jutsu absorption arm so his Absorption Sphere cancels out Ao's, allowing him to land the Rasengan.

As Boruto and Ao exchange words from their time at the thunder train, the team notices drones in the sky that are under Ao's control. Katasuke surmises they respond to Ao's chakra. Boruto comments on how un-shinobi Ao has become, and Ao is steadfast that Kara saved him and allowed him to transcend into a new existence. Boruto asks Sarada and Mitsuki to protect Katasuke and Konohamaru, and faces Ao head on. Boruto uses the absorption arm to absorb the attacks and utilises explosive tags to destroy the drones. As Boruto questions why Ao didn't return to Kirigakure, Ao answers he was waiting for death as a shinobi. He couldn't stand no longer being a shinobi. Ao commends Boruto for pushing him so far, and the two resume fighting. Ao prepares to stab Boruto, who disperses the shadow clone armed with the absorption arm. Boruto emerges from the rubble, and dodging Ao's attack, lands a Rasengan in his weaponised arm, destroying it and sending him against the abandoned building.

As Ao lays in defeat and goads Boruto into killing him, he notes his naiveness for showing mercy. Boruto once again voices Ao's "how it's used" rationale, so even the tools Ao uses should be used for good. He tells Ao to live with the tools Katasuke gave him. Konohamaru regains consciousness, and wants to take Ao back to Konoha when they get reinforcements. Katasuke looks forward for the future of the genin. Ao notices and calls out to Koji, who summons a toad.

Koji's Appearance
As the building begins to collapse under the toad's weight, Ao uses Water Release to push Boruto out of the debris' way, and is crushed by the toad. Koji wonders what motivated Ao to use ninjutsu at the very end, and introduces himself after releasing his summon. Koji congratulates the shinobi for defeating Ao, with Konohamaru asking him on information about Kara. Upon no response, Koji seals their movements, and readies himself to incinerate them. Konohamaru breaks free of the seal with one of his own. The two begin to fight, with clashing a Rasengan on both ends, to everyone's surprise. Koji detonates a toad implanted on Konohamaru, which begins to incinerate him. The seal on Boruto's hand activates and spreads, absorbing the seal and the flames on Konohamaru, who collapses. Koji recognises it as Kāma, surprised that Boruto was the one chosen by Momoshiki.

After Boruto passes out from using his Kāma, Koji thanks them for showing him something interesting and proceeds to leave. Frustrated by the lack of context and answers, Sarada attempts to force answers out of him, but is held back by Mitsuki, not wanting to risk their team-mates lives. Koji approves of his judgement, aware his parent is Orochimaru. Later, after having recovered, the group makes a grave for Ao, and wonder about Kara. At Kara's base, Amado leaves his work station for a moment, and Delta sneaks in to check on the files on Code. Considering him and Boro clean, she considers Koji to be the traitor. Meanwhile, Konohamaru wants to return to the village due to the significant amount of information collected. Chamaru draws their attention to a passed out boy, who they believe to be the one who defeated the puppets. Despite Konohamaru's warning, Boruto approaches him, and notices he has the same mark as him.