One Technique (一つの術, Hitotsu no Jutsu) is chapter 596 of the Naruto manga.
Noticing a slight crack on Tobi's mask, Guy and Naruto thought that Naruto's last attack had actually hit the mask; however Kakashi disagrees, noting that the type of crack was not consistent with a punch, but a sharper object. Kakashi then remembers the lightning-imbued kunai he had thrown earlier at Tobi and had warped away with Kamui. B takes the opportunity to strike the Demonic Statue of the Outer Path as it continues to transform into the Ten-Tails, but the attack is deflected when Tobi erected a barrier, rendering the team powerless to strike the statue until they defeated him. After he had finished formulating his strategy, Kakashi then tells the group to aid him in testing his hypothesis. They then leapt unto B's hand, who launched them directly at Tobi, commencing the plan. Guy starts off using his Sōshūga only for Tobi to avoid it using his dematerialisation ability, predicting Guy's moves with his Sharingan. Jeering Tobi, Guy gets the masked man to absorb his nunchaku rendering him tangible. This allows Naruto to follow up quickly by launching a Rasengan, which Tobi phases through, insisting on the futileness of the strategy. However, the Rasengan seemingly dispersed before passing through Tobi, continued by a sudden explosion that inflicted his right arm and hurled him away, having him to get on his feet again thanks to his weapon. Tobi then realised that the attack was transported to the other dimension using Kamui, just as he was about to materialise. Realising Tobi's ability now, Kakashi notes that Tobi was not using two separate techniques to dematerialise and warp things away, but a single technique.