"Fukasaku's Proposal" (フカサクの提案, Fukasaku no Teian) is chapter 408 of the original Naruto manga.
In Kumogakure, Taka interrogates a Kumo ninja about the Eight-Tails' jinchūriki. By using his Mangekyō Sharingan, Sasuke is able to find out where he is. In Konoha, Naruto asks Fukasaku about the meaning of Jiraiya's dying message: "the real one is not among them". Fukasaku cannot offer any likely theories on how it relates to Pain. With the study of the other clues Jiraiya left behind still ongoing, Fukasaku offers to teach Naruto senjutsu to prepare him for his inevitable encounter with Pain.