The next day, early in the morning, the Nawaki family home.
Kirito himself got up promptly at six o'clock. He quickly got dressed and finished washing up, then quietly sat in the quiet courtyard, concentrating on his daily chakra refinement training and natural energy absorption training, using this method to persistently increase his upper limit of chakra and upper limit of natural energy.
An hour later, he reopened his eyes and then slapped his hand on the ground.
A large number of sealing techniques spread out across the ground, and a square sealing formation rapidly took shape.
Sealing Technique: Four-Point Seal!
Having completed the arrangement of the sealing formation, Kirito extended a hand, and a blue mass of chakra suddenly began to rapidly gather at the palm of his hand, where a small chakra ball began to spin rapidly within.
Rasengan!
Next, he began to slowly infuse the chakra ball with natural energy.
In an instant, the size of the Rasengan increased at a speed visible to the naked eye, rapidly changing from the size of a ping pong ball to that of a volleyball, and emitting a terrifying and unique chakra fluctuation.
This unique chakra was precisely the Senjutsu chakra.
If not for the seal barrier at this time, this terrifying fluctuation of Senjutsu chakra would have definitely alerted many people.
Senjutsu Rasengan!
"Still too slow,"
Kirito sighed as he looked at the Rasengan formed from the senjutsu chakra in his hand.
He had a sage body, so naturally he had set his sights on sage mode from an early age. After he learned how to condense chakra, he had actually been secretly trying to cultivate sage mode, but unfortunately due to his consistently insufficient chakra, he had been unable to do so.
Things started to turn around the day he raised his Yin attribute to 5 and successfully released Rasengan.
Natural energy seems to be much more advanced in quality than chakra, and a little natural energy requires many times the chakra to be mixed in order to create a sage chakra.
The birth of the Sage mode is actually the perfect fusion of the body's chakra and the external natural energy, which then covers the entire body with sage chakra. However, in order to maintain the Sage mode, one needs to have a large enough amount of chakra.
Kirito's current situation is that his own chakra is insufficient, and he is unable to generate enough sage chakra to cover his entire body.
The danger of cultivating the Sage mode is that once a ninja begins to fuse chakra with natural energy to form sage chakra, it is difficult to reverse the process. Natural energy from the outside world will continue to pour in, rapidly depleting the ninja's chakra.
Once the ninja's body lacks enough chakra, the continuous influx of natural energy from the outside world will pose a fatal threat to the ninja, causing huge side effects such as petrification and death by explosion.
Due to his sage body, Kirito can interrupt the influx of natural energy from the outside world at any time, so he does not have to worry about the side effects of natural energy. However, due to his lack of chakra, he cannot enter sage mode and can only create a certain amount of sage chakra.
If a ninja is unable to enter sage mode, the stability of the sage chakra is seriously lacking, and it is very easy to break down again into chakra and natural energy, and it may even explode.
This unstable sage chakra obviously cannot be used to release ninjutsu, and basically it is useless except for allowing him to create the Night Seal.
Later, he discovered that he could form a stable sage chakra outside the body using the Rasengan, which allowed the sage chakra to be used in Jutsu without any problems. However, this only allowed the Rasengan to evolve into the Senjutsu Rasengan, and other Jutsu still could not be evolved into Senjutsu.
Moreover, the speed at which the Senjutsu Rasengan could be released was still too slow, and Kirito believed that it had not yet reached the basic requirements that would allow it to be used in combat.
"Take your time. It's time for breakfast."
Kirito quickly gathered his thoughts, then removed the seal and walked towards the living room.
When he arrived, the maid in the house had already prepared breakfast.
However, there was an extra person at the table today. It was a hot blonde beauty with a hot body, and it was Nawaki's sister, Tsunade.
She was wearing a loose white yukata at the moment, with a large expanse of snow-white stuff showing from the neckline. She had a bare face, her eyes were a bit dazed, and her hair was a bit messy, so it looked like she had just woken up.
"Kirito, let me introduce you. This is my sister, Tsunade. She's a Konoha hero."
Nawaki saw Kirito and immediately excitedly introduced his sister to him, with a proud expression on his face.
"Tsunade-sama, it's a pleasure to meet you. I am Kirito Tosaka. I'm currently an intern medical ninja at the hospital. I hope we can get along in the future."
Kirito respectfully bowed to Tsunade, looking at her with a hint of adoration in his eyes.
Tsunade returned late last night. As soon as the other party approached within 11 kilometers of Konoha, he sensed the other party's spiritual energy, but pretended not to know.
When Tsunade heard Kirito's words, her big, confused brown eyes suddenly cleared up.
She turned her head and surveyed Kirito, a smile suddenly appearing on her face. She smiled and waved at Kirito, saying, "Come over here for a bit, brat."
Kirito was confused, but he did as he was told.
Who knew that as soon as he got close to Tsunade, she would wrap her arms around his neck, pull him into her embrace, and then start furiously rubbing his hair with her other hand, laughing, "Why're you calling me Tsunade-sama? It's so polite. You are my grandmother's favorite disciple and a good brother of Nawase. Thank you for taking care of Nawaki, a fool, all these years. From now on, call me sister like Nawaki, do you understand?"
She had been fighting on the frontlines in the Land of Rain for many years, and although she had never returned to Konoha, she had kept in touch with Mito and Nawaki through letters. Naturally, she had learned a lot about Kirito, and knew that Mito and Nawaki both liked him very much and considered him like family.
Kirito had also helped Nawaki a lot, and it was because of him that Nawaki had grown up so quickly.
In fact, she was shocked to discover when she returned that Nawaki had already reached the strength of a special jōnin.
She has experienced war and knows very well how important strength is in these troubled times, and how dangerous it is for Nawaki in this chaotic world.
Therefore, she learned from Nawaki that Kirito often accompanied him in training, and even guided his training, passing on his own self-created ninjutsu to him. She was able to become so strong without Kirito's help, and she is truly grateful to him from the bottom of her heart.
"wuwuwuwu"
Tsunade was very strong, and Kirito was completely unable to resist. At this time, he was being suffocated and was unable to carefully appreciate this wonderful attack.
"Sister, stop, Kirito is about to be suffocated to death by you."
Nawaki knew how terrifying his sister's facial cleanser attack was. He watched Kirito being treated like this and deliberately paused for a while, waiting until Kirito was about to die before he hurriedly persuaded him.
"Ah, I'm sorry, I got a little carried away."
"It's okay, Tsunade-sama, I'm fine,"
Kirito gasped, looking at Tsunade's chest with a lingering fear in his heart. He felt that if Nawaki had spoken any slower, he would have suffocated.
But as soon as he said this, he regretted it. He suddenly noticed that Tsunade in front of him was smiling at him.
That kind expression, Kirito had seen before in Mito.
He immediately changed the subject smartly and said, "Sister Tsunade, let's eat, I'm hungry."
"Okay, Kirito, let's eat together."
The words 'Sister Tsunade' immediately made Tsunade put away the kind expression. She gently patted Kirito's head and smiled contentedly.
Suddenly having an extra cheap sister, and this sister was still Tsunade, Kirito felt strange at first.
However, he could feel the pure goodwill coming from Tsunade. Like many people in the Senju clan, she gave him a very sunny and kind feeling.
To be honest, it was actually pretty good to have such a beautiful and powerful sister. At the very least, he could openly and honestly get all kinds of advanced medical knowledge from Tsunade for free in the future.
He believed that with Tsunade's top-notch medical ninja teaching him by hand, his medical knowledge would definitely see another leap forward, and perhaps there would soon be a new breakthrough in the cell fusion technique that had always troubled him.
At this thought, Kirito couldn't help but smile a little when he ate.