The Yin Release Barrier was different from real space. It would not manifest in reality, and its spatial dimensions and time flow were different, but it was still a real, existing space. Retsuo had been developing this barrier all along, but he suddenly realized that he had only been developing ways to use it, rather than studying its essence.
If he wanted to study its essence, he had to go inside and take a look! A strand of Minato Namikaze's Chakra had managed to do it, so Retsuo didn't believe he couldn't.
Yet he really couldn't do it. Retsuo could clearly sense that the barrier was there, but it was missing a door and a passage!
Minato Namikaze was, after all, an expert in Space-Time Ninjutsu. He had an advantage in this regard. What should Retsuo do?
That's it! Inspiration struck Retsuo, and he hurriedly took a Flying Thunder God Kunai from the Sealing Scroll.
This was evidence, of course, and it had to remain in the informant's hands. Danzo really wanted it, but how could Retsuo possibly give it to him?
At that moment, instead of waiting for Minato to come out on his own, he immediately gathered his Chakra and charged the barrier with dense Yin Release, though he didn't smile.
He wanted to recreate the conditions from back in the dense forest.
Soon, a sucking force came from the Yin Release Barrier. Retsuo smiled knowingly and immediately went with the flow. The next moment, his consciousness appeared inside the barrier space.
"Teacher Minato!"
Seeing Minato Namikaze standing before him with a dazed expression, Retsuo became excited. Since crossing over, Minato was the person who made him feel the most secure, followed by Ukyo and Yulong, then Tenma and Shinji.
"Retsuo, is that you? Am I already dead?