"Proof" (証明, Shōmei) is chapter 39 of the Boruto manga.
Kawaki stares at his fallen prosthetic hand. Sarada asks him what happened. Boruto and Mitsuki arrive. Sarada tells them Naruto is missing. Shikamaru arrives with backup and pins Kawaki down with his shadow. Shikamaru says what the Sensor Unit reported to him and demands an explanation from Kawaki. He gives a signal to a subordinate, and a barrier goes up around the house. Shikamaru explains it's to both keep Kawaki from fleeing and keeping enemy reinforcements out. Shikamaru orders his subordinates to look in the house in pairs for clues. He unpins Kawaki and asks what happened. Kawaki explains Jigen suddenly appeared when his Kāma began hurting, forming a a crack in the air. Shikamaru recognises it as space–time ninjutsu. Sarada questions why he'd take Naruto if he was after Kawaki, who explains it was to eliminate Naruto for interfering. Shikamaru and Mitsuki note that if it was just to take him out of the day, it would only take a moment, leading Shikamaru to deduce they're either still fighting, or that best case scenario, Naruto defeated Jigen but can't come back. Boruto mentions Sasuke, who he knows to have space–time ninjutsu, but Shikamaru hasn't heard from him since his most recent mission. Shikamaru asks if there's anything else Kawaki hasn't said. He bluntly says he has never trusted Kawaki, and suspects Kawaki has been a Kara member all along, Naruto's disappearance only deepening his concern. Kawaki finds no fault in his logic. With Naruto absent, it falls on Shikamaru what to do with Kawaki, so he decides for house arrest until they have proof he's not a spy. Boruto protests but Kawaki accepts it. Koji finds the situation unusual. He determines that Jigen ended up using too much chakra, and finds it a rare opportunity of being able to take Jigen down himself, and leaves to head back to base. Amado tends to Jigen and determines it'll take two days for his chakra to fully recharge. Jigen says he got carried away by how happy he was, due to how Kawaki's Kāma is developing. Amado speculates if that is due to the resonance with Boruto's Kāma, an idea Jigen supports. Jigen believes they'll both become powerful Ōtsutsuki, and a giant God Tree will grow. He reassures Amado his wishes will be granted. Amado glances at Delta, who tells him off. Boruto refuses to believe Kawaki is a spy, but Shikamaru explains he has to be contained because they can't tell it either way. Boruto brings up Kawaki sacrificing his arm to protect Naruto and Himawari, but having heard Kara's scientist might be able to fix it, Shikamaru things it would be a good way to earn their trust, and if there is a plan, they wouldn't try killing one of their own. Kawaki thinks of Naruto, and wonders why he was good to him. Sarada understands him, and reveals she has wondered how her life would be better if Naruto was her father. She confesses being jealous of Boruto, and annoyed at his ignorance of how lucky he is. While Boruto is arguing with Shikamaru, one of his subordinates arrives with the repaired vase, wondering if it's a tool for a jutsu. Boruto takes it, berating him for thinking something so stupid, and marvels at it being fixed. Kawaki points out he's the one who complained about it, and that there's still a small hole in it. Shikamaru still doesn't accept it as proof Kawaki isn't a spy. Kawaki's prosthesis lights up with Naruto's chakra, Kawaki taking it as proof Naruto is alive. Kawaki can sense Naruto's chakra through the prosthesis, and looking at his Kāma, he asks for Boruto's assistance. Kawaki activates his Kāma, forming a portal like Jigen's, and Boruto's Kāma resonates, activating and contributing to the portals formation. Kawaki makes a realisation he can do the same things as Jigen because he's like him, and decides to go rescue Naruto. Boruto denies Kawaki is anything like Jigen. Shikamaru pins the children with his shadow, with no intention of letting them go. Kawaki breaks it by absorbing it, and warns the portal will close soon. Mitsuki grabs Sarada and Boruto and jumps through. Kawaki goes through it, telling Shikamaru he's going to get his proof. They arrive at another dimension, and find Boro guarding the kettle containing Naruto. Boro and Kawaki recognise one another, and Kawaki explains Boro is also a Kara Inner, and in some ways, worse than Jigen.