Reincarnation to the world of Naruto

Dodo bit his thumb and then wrote his name with his blood. After writing his name, he pressed three fingers beneath it as a signature.

Once Dodo finished, Gamamaru took the scroll with his tongue and swallowed it whole.

"I’ve always wondered… how can your stomach hold so many different things?" Dodo asked in confusion.

"Alright, let's begin the first stage of training," said the toad, ignoring Dodo’s question.

Gamamaru taught Dodo how to meditate and gave him guidance.

Dodo nodded and began meditating, training his spiritual calm and balance. On his first try, he succeeded in mastering both.

Gamamaru's eyes widened in surprise. He was amazed that Dodo had achieved it so quickly. Gamamaru allowed Dodo to continue meditating for several days while he went out to meet Hagoromo.

Time passed quickly—three days had gone by, and Dodo was still holding his meditation.

Smack!

“Ouch! Why did you hit me?” Dodo yelled angrily. A bump had appeared on his head. He held it and gently rubbed the swelling.

"Follow me, we’re starting the second stage of training," Gamamaru said as he leapt away.

Dodo stood up and followed him. When they arrived, Dodo saw massive toad statues. There was also a yellow-colored pond nearby, which functioned to help absorb natural energy—but it came with side effects.

Dodo recognized the pond and smiled, remembering how Naruto used to get smacked over and over for jumping in carelessly. “Will I turn into a toad too if I jump in?” he wondered.

Gamamaru noticed Dodo smiling and squinted at him suspiciously. “Why are you smiling? Do you know this place?” he asked curiously.

“Uhm… no, this is my first time seeing it in real life,” Dodo answered.

Gamamaru eyed him suspiciously, then began explaining the second stage of training. Dodo nodded in understanding—he actually already knew the stages, so he simply followed the instructions given.

Dodo sat down to meditate near the pond, and Gamamaru dabbed some of the pond’s water on his body.

Gamamaru stood ready to smack Dodo if his body began to transform. But after some time passed, the transformation never happened. Gamamaru continued observing Dodo’s progress. Time flew by—it had been a week since the second stage began.

“I can’t believe it… this child is truly gifted. In just a few days, he managed to absorb natural energy without any side effects. Not even the slightest transformation,” Gamamaru said in awe.

Dodo, still meditating, slowly opened his eyes. He could feel something different about them. When he looked at his reflection in the pond, he smiled in satisfaction. “Finally! My Rinnegan has awakened!” he said proudly.

Gamamaru was shocked when he saw Dodo’s eyes. “That’s impossible! That kind of eye is only gained through the sacrifice of a loved one… How could it be awakened just by absorbing natural energy?” he exclaimed in disbelief.

He shook his head, then congratulated Dodo for mastering natural energy absorption. “Congratulations! You’ve mastered the technique of absorbing natural energy. So, what will you do next?” Gamamaru asked.

Still gazing at his reflection, Dodo turned around. “I’ll stay here for a while longer to absorb more natural energy.”

“You should know that it’s pointless. Natural energy only lasts a few minutes in a human body,” Gamamaru replied.

Dodo smiled at his words. “I have my own method,” he said with an unreadable expression.

“Suit yourself… I’ll be leaving for a while,” Gamamaru said as he walked away.

“Alright, Satek! Let’s convert this natural energy into chakra,” Dodo muttered as he sat in a lotus position.

He closed his eyes. The natural energy he absorbed wasn’t stored in his chakra core, but in a newly created dantian.

Before he had brain cancer, Dodo used to read a lot of Eastern fantasy novels. He never imagined that reincarnated main characters could actually be real—because now, he had experienced it himself.

Dodo began transferring the natural energy into his chakra core. At first, it was difficult, but after some time he began to understand the process. He smirked.

“It’s actually quite easy to convert natural energy into chakra,” he thought.

Dodo spent a whole day converting the energy. He opened his eyes and smiled with satisfaction. “My chakra is almost equal to a Bijuu now!” he said with a proud grin.

He closed his eyes again and continued absorbing energy into his dantian. He no longer needed food, as the energy he absorbed nourished his body.

Time passed. A whole year went by as Dodo continued absorbing energy. His body was covered with birds perching peacefully on him. Dodo opened his eyes and decided it was time to stop.

“This must be my limit… I need something that can help me store even more natural energy,” he said while sensing the energy in his dantian.

Suddenly, he smiled. He remembered the Divine Tree. “I need to get the Juubi’s soul and turn it into the source of my dantian. Hahaha!” Dodo chuckled darkly.

He stood up and began searching for Gamamaru. “Gamamaru, where are you?” he shouted while looking around. “Hmm… looks like he’s still not back.”

Outside Mount Myoboku, chaos had broken out. The battle between Kaguya and her two sons was tearing the land apart, causing massive tremors.

“Ah, I should convert more of this energy into chakra,” Dodo said as he turned to head back to his meditation spot.

But just as he was about to walk, a powerful tremor shook the ground. “W-what’s going on?” he muttered, startled.

“This isn’t just a normal tremor… it feels like it’s caused by a battle,” he said, placing a hand under his chin.

“Has their fight already started? I can’t miss the chance to claim the Juubi’s soul.”

Dodo ran toward a river and jumped in. He dived to the bottom, and suddenly found himself in a different location. Emerging from the water, he looked around—then another quake struck, this time more violent, followed by a series of explosions.

“It’s nearby! I have to hurry!” Dodo shouted as he leapt from tree to tree.

Explosions rang out again. Dodo increased his speed, and after a short while, he arrived at the battlefield.

“Looks like Gamamaru is fighting Kaguya too. But wait… since when did he get that big?”

Gamamaru’s size nearly matched the Juubi’s. “Should I help them? No, no… if Kaguya targets me, she’ll turn me to ash. I’d better just watch for now.”