"The Battlefield, Konoha!!" (戦場、木ノ葉!!, Senjō, Konoha!!) is chapter 420 of the original Naruto manga.
Naruto continues to train with Fukasaku. While taking a break, Fukasaku informs Naruto that it is almost impossible to use Sage Mode by one's self in combat. Naruto believes his training has been a waste of time, but Fukasaku explains that they can fuse together to overcome this disadvantage. Elsewhere, the invasion of Pain underway. Iruka is found by the Deva Path, who asks where to find Naruto. Iruka refuses to tell him anything. The Deva Path tries to kill him but he is saved by Kakashi. Kakashi and the Deva Path start fighting while Iruka escapes, but Kakashi finds that he cannot get near the Pain for some reason. Meanwhile, Shizune finds that Pain's body piercings are really chakra receivers. News of Pain's invasion begins to spread through Konoha and Tsunade calls for Naruto's return.