Perhaps Minato's entrance had been too shocking. Naruto's emotions had remained in a strange state, somewhere between happiness that wasn't quite happiness and surprise that wasn't quite surprise.
Admittedly, when Naruto heard that he could still meet his father, he had been genuinely thrilled.
The very fact that he had a family, that he had a father, was the best news he could have asked for!
But honestly, faced with this ball of "ghost fire," he couldn't quite feel happy from the bottom of his heart.
In fact, more than the reunion with his "father," what overwhelmed him was his astonishment at the Nine-Tails. He hadn't imagined that the creature inside him could actually summon his father's "departed spirit."
This was his first time seeing a real "ghost." It had certainly opened his eyes!
He was even a tiny bit scared.
"Naruto, it's been a while. You've grown so much."
Minato's chakra flickered, his voice gentle.
"Dad... wait, are you really my dad?"
Naruto stammered a little. The scene before him was simply too bizarre.
"Minato, why don't you change your appearance before you say anything else?"
The Nine-Tails finally couldn't stand watching anymore and chimed in.
Minato: "..."
"What is it?" the Nine-Tails asked in confusion.
"Actually... it's not that I want to look like this. It seems I can't return to human form just yet."
Minato answered awkwardly. After awakening, he had told the Nine-Tails that he was eager to see Naruto. Only now, after appearing before him, did he realize that he couldn't yet change out of this ball-of-chakra form.
"...Could you at least get your act together a little?"
Despite its words, the Nine-Tails readily stepped in to help Minato adjust his chakra.
As the Nine-Tails slowly fed in its red chakra, Naruto watched in shock