Ninjas who had eaten the White Zetsu Chakra Fruit and Kekkei Chakra Fruit would live for at least several centuries. Women like Tsunade, who possessed exceptional talent and received Sarutobi Toru's attention, could easily live for thousands of years.
So there was no concern that by the time the Otsutsuki Clan learned the news and came to the Shinobi World, everyone from Sarutobi Toru's generation would already be dead.
Besides, the Otsutsuki Clan was the best material for feeding the God Tree, and Sarutobi Toru was fundamentally at odds with them.
After all, he wanted to turn every last one of them into fertilizer!
"Even though I've decided to leave, I still need to cultivate the younger generation of the Shinobi World. Right now, aside from me, no one else can produce all kinds of Chakra Fruits."
"At the very least, I should wait until Chakra Fruits no longer work on them and their strength has basically taken shape before I truly leave."
"That will probably take another three to five years. At the same time, I need to deal with the hidden danger of Otsutsuki Kaguya on the moon."
"Perhaps I can try using the Hormone Fruit ability to control Otsutsuki Kaguya. Though she's sealed away, with my Space-Time talent, I should be able to manipulate the hormones inside her body from afar and communicate with her through my soul. I should be able to persuade her."
With that thought, Sarutobi Toru silently made up his mind. He stored the God Tree back into his Pocket Dimension, left the Ancient Kingdom of Rōran, and returned to Konoha.
During the remaining time, Sarutobi Toru began stockpiling and producing all kinds of Chakra Fruits on a massive scale. As scientific technology in the two Shinobi Worlds developed, cloning technology also steadily