Naruto was very sad today and started doubt his own life. Just then one of the academy teachers mizuki approached Naruto and told him about the scroll of seals. Naruto being a simple hearted person believed mizuki without a single doubt. Naruto went to find the scroll of seals. He found it very easily as if it was placed to attract Naruto's attention. As soon as he found it he ran like hell while he was thinking " finally I got it. After I master all this jutsus I will finally become Hokage. Believe it!"
Iruka heard what happened from the Hokage. At first when he meet Naruto he was like most people. He disliked Naruto. After all his parents died in the attack of the nine tails. But over time he found that Naruto was just like any other kid. His hard working and haughty nature made Iruka see himself in Naruto and he finally acknowledged Naruto. Iruka immediately went to look for Naruto.
Hiruzen for long time knew about the true nature of Mizuki. So he made a plan that will trap him and test Naruto at same time. At first he created a fake scroll of seals and put ninjutsus that will benefit Naruto in it. Then he leaked the information to mizuki and put it in a place where Naruto can easily steal it. Then he waited for Mizuki to take the bait. When everything was happening he was keeping an eye on from the crystal ball. When Naruto stole it he called some idiots who will never find Naruto to look for him. He also called Iruka and leaked the news to Kizo with the help of anbu.
In the forest Kizo was looking looking for Naruto with a very complicated expression. Naruto was first and best friend in the world. He could not bear the thought of something happening to Naruto. He still remembers the dark times of his life before he met Naruto. He thought "no matter what happens I will never let anything happen to Naruto" .Just then he saw Naruto being chased by Mizuki. Unknown to him it was Iruka who transformed into Naruto. Things happened just like in the original. Mizuki said that Naruto was the demon fox and Iruka gave speech about Naruto which touched Naruto to his soul. Just than Kizo showed up. When he heard about Naruto he was the demon fox he was stateled by it. But when he heard what Iruka said he quickly recovered. He came out of the trees and said, "that's right. Naruto is my friend and that's the only thing I care about. I will never let anything happen to my friend."
When Naruto heard it he again shed his tears. But he quickly wiped his tears and came out of hiding. " I am not the demon fox. I am Naruto uzumaki who will become Hokage. Believe it!" As he said that Naruto used multi shadow clone jutsu and created hundreds of showdow clones. This scene shocked everyone present. Then all his clones jumped on Mizuki. Mizuki didn't last long against all this clothes he was quickly beaten by Naruto.
Hiruzen who saw that scene in the crystal ball could not be more satisfied. This whole this work out way better that he had expected. He could not help but say, "Minato your son is gonna a great ninja just like you maybe even better."