Jiraiya staying behind to teach Yahiko and Nagato was merely a small interlude in the war.
Just as Jiraiya had said, now that the course of the war was gradually becoming clear, it could still end even without his strength. The situation had already shifted in Konoha's favor.
And with Jiraiya's current strength and status, he also possessed considerable autonomy on the battlefield.
Thus, not far from the cave where they had met, Jiraiya used ninjutsu to build a house, and he settled down there with the two boys.
The long-lost feeling of having a home deeply moved the two boys. That very evening, Nagato even burst into tears at the dinner table.
After that, they truly settled there. Yahiko kept pestering Jiraiya to teach him ninjutsu, but Jiraiya remained reluctant to teach them.
He was still hesitant. The path of a ninja was difficult, and he did not want these two children to embark on a road of no return. So he kept putting it off. As for what he would ultimately decide, even he did not know.
This continued for around ten days. Jiraiya, having settled down, enjoyed a rare period of peace—until something suddenly happened.
Dark clouds gathered across the sky, and heavy rain pelted the roof with a crackling patter. Dressed in a casual sweater, Jiraiya sat inside and turned to look out the window. Water gathered on the glass, streaming rapidly downward like countless tiny rivulets.
After watching the rain for a while, he set down the brush in his hand. He had intended to use this time to write something, but he still could not bring himself to put pen to paper.
Second by second, time passed. The sky had grown completely dark. Jiraiya checked the time. It was already eight in the evening.