The Secret of the Space–Time Ninjutsu (時空間忍術の秘密, Jikūkan Ninjutsu no Himitsu) is chapter 597 of the Naruto manga.
Urging Kakashi to explain it in the simplest way possible so that they could readjust their strategy, Guy and the others listen on as Kakashi explains that Tobi's ability to become intangible and absorb things were one and the same. He then explains that when he makes himself intangible, what Tobi actually does is to warp away the part of his body that was being attacked to the other dimension; so while it existed there, all attacks would simply phase through his body. However, since Kamui shares the same dimension, the lightning-enhanced kunai that Kakashi warped away, passed through the "intangible" part of Tobi's body and ended up in the other dimension and scratched the part of his body that was sent there in order to make him appear intangible. When questioned by B how it was possible that their two techniques were linked to the same dimension, a hesitant Guy began to question Kakashi, but the latter cuts across him to ask Tobi directly where he got the Sharingan from. Responding, he told them that he got it during the previous war at the Kannabi Bridge at a time when Kakashi was being recognised as the "Hero of the Sharingan" (写輪眼の英雄, Sharingan no Eiyū; Literally meaning "Hero of the Copy Wheel Eye"). With the Copy Ninja at a loss for words, Tobi takes the opportunity to chastise him and perpetrate his Eye of the Moon Plan as the right move for humanity, but his views are still rejected by Naruto who tells him that he would not give up his dreams. Taking the opportunity to chastise his beliefs as well, Tobi questions Naruto on how he would feel when he failed Jiraiya and Minato. Telling its jinchūriki to switch with it, however, Kurama speaks directly to Tobi telling him that it was entrusted to Naruto, who had befriended him, for the express reason of defeating Tobi. Spurring the young man onwards, Naruto enters his Tailed Beast Mode and charges towards the masked man.