Chapter 288 : Experiment!

Kazuhiko didn't come to Shikkotsu Forest just for a romantic meeting with Tsunade; he had other important matters to attend to. Primarily, he wanted to discuss the latest developments regarding Hiruko.

Since Tsunade was one of the few people who had a friendly relationship with Hiruko, Kazuhiko had asked her to keep an eye on him and report anything unusual. 

She knew that Hiruko was a somewhat sensitive person, but she didn't realize just how much Kazuhiko valued him.

For a while, the two of them sat in comfortable silence, allowing Kazuhiko to relax and momentarily forget about his responsibilities back in the Land of Red. There was no need to rush around or worry about other matters—just time to be with someone he cared about.

After a period of peaceful quietness, they decided it was time to get back to business. As they stepped outside, Kazuhiko turned to Tsunade and asked her about Hiruko's current activities.

Tsunade had previously wondered why Kazuhiko seemed so interested in a relatively obscure ninja from Konoha. 

But Kazuhiko had explained, "I think Hiruko is a rare talent. Not necessarily in terms of ninja skills, but he has potential in other areas."

Tsunade accepted this explanation and agreed to provide regular updates about Hiruko's activities during their meetings in Shikkotsu Forest. On this particular day, she shared something interesting.

"If it weren't for you, Kazuhiko-kun, I might not have noticed. Hiruko has been acting a bit secretive lately, as if he's involved in some kind of clandestine project."

Kazuhiko nodded, realizing that Hiruko must have begun his experiments. "Got it. Just keep an eye on him. There's no need to interfere too much."

Tsunade agreed and didn't press the issue further. In her eyes, Kazuhiko was someone who had his own reasons and plans, and she trusted his judgment. If he needed her to know more, he would tell her in due time.

After spending time together, she had come to understand this man better and better. He had a remarkable ability to see the bigger picture, perceiving things that many others couldn't.

Perhaps his latest decision seemed confusing to everyone at first, but in time, they'd understand his intentions. It would just take a while for people to process and react to it, and then his motives would become clear.

Kazuhiko was also quite pleased when it was confirmed that Hiruko's defection had likely happened around this time. 

He retrieved an experimental prop that he'd set aside earlier—a mouse. There were several mice in the cage; some were dead, some were lethargic, and others were lively and energetic. Tsunade and Kazuhiko watched them quietly.

"Kazuhiko, are these your lab mice?" Tsunade asked, her curiosity piqued.

"Yeah," he replied, focusing on the mice. These creatures had become crucial for his experiments.

In the ninja world, it wasn't uncommon for ninjas to die from exhausting their chakra after intense battles. Chakra, as he saw it, was a key element that sustained life. Yet, some people were born unable to extract chakra from their bodies.

Indeed, if you refine chakra but then lose it all, your body would shut down, leading to death.

Although there were many reasons why a person might die, chakra exhaustion seemed to be a unique cause. Kazuhiko had quickly concluded that this type of death was linked to natural energy.

If a person couldn't refine chakra or if they depleted their chakra completely, the key to both situations was the transformation of natural energy into chakra.

In this world, even if someone couldn't refine chakra, their survival still depended on natural energy in one way or another.

Kazuhiko speculated that death due to chakra exhaustion might indicate that his body had depleted its natural energy reserves. 

Essentially, chakra is a diluted form of natural energy, and since over 99% of the world's population cannot harness natural energy, they fall back on mastering chakra instead.

Kazuhiko's theory was that when chakra was depleted to the point of death, it could be due to the excessive use of the body's own natural energy reserves. 

To test this theory, he began conducting experiments with mice in the Shikkotsu Forest. With Sage Katsuyu's guidance, he became more proficient at controlling natural energy, making the Shikkotsu Forest an ideal experimental location.

Though he hadn't solved the mystery entirely, Kazuhiko was quite pleased with his experiments' progress. 

He found that by injecting mice with a saline solution containing natural energy, he could replace their depleted chakra and sustain their life functions for a limited time.

During these experiments, Sage Katsuyu assisted by observing the effects of natural energy on the mice. 

Despite Kazuhiko's own Observation Haki, his grasp of natural energy wasn't as refined as Sage Katsuyu's, who had centuries of experience.

To aid his research, he had some of Sage Katsuyu's smaller clones monitor the mice. Since Kazuhiko couldn't dedicate all his time to watching the mice, he relied on Sage Katsuyu's help for this task.

Interestingly, Sage Katsuyu didn't know the ultimate purpose of Kazuhiko's experiments, but she found the work intriguing and was glad to help, especially since it relieved her boredom. 

Besides, where else could they find a more suitable environment for these experiments than the Shikkotsu Forest?

Over the past few days of experimentation, Kazuhiko has been conducting tests without any interference from other types of energy—only salt water containing natural energy is used in the process.

By extracting chakra from a few test mice, he made some interesting discoveries.

When chakra was removed from the mice, even though they were quickly treated with the salt water solution, they couldn't avoid death.

However, the mice that were injected with natural energy displayed different behaviors. Some seemed sluggish, while others remained active and full of energy.

Kazuhiko has been closely observing these mice over the past few days to better understand the effects of natural energy in their bodies.