"The story of this ninjutsu began with the Fourth Hokage, Minato Namikaze..."
Back then, Minato Namikaze had yet to reach his full potential. His strength was a far cry from what it would be when he became the Fourth Hokage, but he remained determined to grow stronger.
He followed Jiraiya on missions, learned new ninjutsu, trained, and constantly honed his skills, gradually becoming someone who could hold his own.
At the time, Minato was dating Kushina, but her status as a jinchūriki meant she could not move around freely. It was a form of supervision in all but name. Moreover, the seal inside her was not very stable, and the Nine-Tails would break loose and go berserk from time to time.
This made life miserable for the people of Konoha, but out of respect for the previous Nine-Tails Jinchuriki, Mito Uzumaki, no one went looking for trouble. Such was Mito's intimidating presence that even after she was gone, they dared not immediately step forward. Who knew whether she was truly dead? What if she had only faked her death?
But as time passed and Mito's influence waned, sooner or later someone would set their sights on Kushina. As her boyfriend, Minato not only had to withstand enormous pressure but also had to hurry to improve his strength. In short, time was tight, and there was much to do.
Minato did not have much time left.
On another mission outside the village, he accompanied Jiraiya and Tsunade. This time, luck was not on their side: they encountered two tailed beast jinchūriki in succession, the Four-Tails Jinchuriki, Roshi, and the Five-Tails Jinchuriki, Han.
Unable to defeat the Konoha ninja, the two unleashed their tailed beasts' final forms. Two enormous tailed beasts appeared: the Four-Tails, Son Goku, and the Five-Tails Kokuō. In those