"Unease" (胸騒ぎ, Munasawagi) is chapter 370 of the original Naruto manga.
The Amegakure ninja refuses to tell Jiraiya anything about Pain's current activities. Jiraiya leaves him, admiring his loyalty. Jiraiya removes Gerotora from his body, explaining that he is worried about confronting Pain. He tells Gerotora to store himself within Naruto if he doesn't return. Gerotora, containing the key to the seal that keeps the Nine-Tailed Demon Fox within Naruto, advises against it. Jiraiya insists, believing Minato would want Naruto to master the Nine-Tails for some unknown purpose, perhaps to combat Madara Uchiha.