[Note: The previous time calculation was wrong. After Yiyong starts school (if he goes to school), it should be the second half of the 4th grade school year. This will prevail from now on...]

When Bai woke up, it was already bright and the gentle chirping of birds could be heard from outside the house.

He turned over and sat up, and surprisingly found that there was no psychological resistance at all when he got up today.

This time, Bai didn't feel anxious about how he was going to get through this day again. Instead, he looked forward to the new day and what interesting things would happen.

【Is it because I met new friends or because I cried a lot yesterday? 】

Bai felt a little embarrassed when he thought about what happened yesterday.

Fortunately, Zabuza-sama didn't catch him crying, otherwise he would have been so ashamed that he couldn't be ashamed of himself.

At this time, the sound of turning pages of paper came from the room, which attracted Bai's attention.

He turned around and saw the butterfly ninja sitting in front of the table, flipping through Giyu's fourth-grade textbook in front of the oil lamp.

Sometimes she frowned and turned the page impatiently, muttering something silently on her lips; sometimes her eyes stayed on a page for a long time and wandered repeatedly, nodding approvingly, as if she was the one who would be inspected for her studies after school started. .She didn't even realize that Bai had woken up from her sleep.

Bai glanced at the sleeping bag on the ground without any signs of stirring, and immediately deduce what happened last night.

He asked softly: "Miss Ren, didn't you have a rest all night?"

Giyuu bought the sleeping bag and put it in the scroll before setting off from Konoha.

He originally thought that the thing would be very commonly used on the road, but now that the trip to the Kingdom of Water is almost over, the sleeping bag is still brand new, and even the label has not been removed. He wonders if he can return it at full price when he returns.

"Miss Shinobu, can you hear me?"

Seeing that there was no response from the other party, Bai called again, but his voice was louder.

"Um?"

This time, the Butterfly Ninja finally woke up from his state of concentration and noticed that it was already bright outside.

"Oh, oh, oh," she pretended to stretch and extinguished the oil lamp. "It's all because the content in this book is so interesting, so I was so fascinated by it that I didn't even know it was dawn. Thank you for calling me. Wake me up, Bai."

Although Giyu's teaching materials have a strong stance and tendency, they still provide her with a lot of common sense in the ninja world.

Among them, the knowledge related to medicine and biology that she was most concerned about, such as chakra meridians and genetic research, were something she had never heard of on earth, so the butterfly ninja was full of enthusiasm and interest in inquiry.

In this aspect, she and Orochimaru are somewhat similar.

For the butterfly ninja who is driven by curiosity, the reading experience last night has undoubtedly sent her to the door of a new world. She can't wait to learn more systematically, but this requires a The necessary foundation - mastering and understanding chakra.

Without this foundation, most knowledge is just castles in the air.

However, Shiro could not understand the thoughts of a scientist from another world.

"Did you stay up all night because you were too worried about his injury?"

Bai glanced at Yiyong, who still showed no signs of waking up, "Actually, you can wake me up when you are tired and take turns taking care of him. Weren't you angry yesterday because he worked too hard on the way?"

"You have already helped me a lot, why should I trouble you again?"

The butterfly ninja closed the book, with the smile still on his face and no signs of fatigue.

"Besides, it is not your responsibility to take care of him. You are not a doctor. If something happens to him, it will be difficult for you to make a correct judgment. Wouldn't you have to wake me up then? Being woken up from sleep is worse than not sleeping at all.

It’s annoying, isn’t it?”

She paused, put her index finger on her chin, and glanced downward.

"But strangely enough, I don't feel tired at all even though I stayed up all night."

The butterfly ninja closed his eyes, moved his body widely, and carefully felt the condition of all the muscles and skin on his body. Indeed, he did not feel the sore and heavy tension that he had in the past after working the night shift.

"It's not just that I don't feel tired, I don't even feel thirsty or hungry. It's really weird."

[Is it because I slept for too long before? 】

She guessed in her mind, "Or is there something special about this body besides being strong?"

"You didn't even drink water all night?"

Bai glanced at the water glass on the table, and sure enough it was still full.

"Miss Ren," he couldn't help but frowned worriedly: "Is it because you have gone through too much, so your feelings have become blurred?"

"No. I have experienced this situation many times while working night shifts. I also know this very well - if a doctor wants to take good care of his patients, he must first take care of himself. Otherwise, once treatment errors occur due to poor condition, it will be a serious mistake.

It can kill people, but I never play with the patient's life."

Butterfly Ninja shook his head and said seriously: "Besides, my feeling of energy is very obvious, and it doesn't seem to be a psychological reason. Bai, I'm really not tired at all. I'm definitely not trying to be brave. Don't worry.

"

At the same time, Shiro's look of worrying about other people's health also activated Butterfly Ninja's memories.

"Looking at your expression, sometimes I feel that you are more of a careful girl than me."

[This child really has the talent to take care of others. He is very similar to Xiao Qing and others.]

Bai's face turned red and he quickly changed the topic.

"So you just read the textbook all night?"

"Not entirely."

The Butterfly Ninja opened Giyuu's notes on Senju Tobirama Ninjutsu and shook the paper full of words towards Shiro.

"The ninjutsu here seems to involve the method of refining chakra, so I tried it as mentioned above."

"Hmm? What's the result?"

Bai's eyes lit up. Whether he has chakra or not is a qualitative difference for humans.

The Butterfly Ninja is already so powerful without chakra. What would it be like if he mastered this power?

"The content above is still a bit vague."

Butterfly Ninja sighed with some regret: "I tried for half a night, but I only have a little clue."

She has not mastered the ability to "transmit the world", so naturally she cannot control the energy inside her body like Giyu, so she can only refine chakra by feeling like most ninjas.

Unfortunately, she has never had any talent in terms of intuition.

"Speaking of which, Bai, how long did it take you to learn to extract chakra? Do you still remember how you felt at the time? Maybe you can give me some reference."

Butterfly Ninja looked at Shiro curiously.

Bai didn't answer immediately, as if remembering some long-lost past event, his eyes drooped slightly and then returned to normal.

"Hey. Do you have any concerns? For example, the village requires confidentiality..."

The butterfly ninja saw that something was not right about his state, stood up, took two steps closer, and comforted him in a warm voice: "It's okay, don't force yourself if you can't tell me. I'm not in a hurry at this moment."

Bai waved his hands palely: "There is no such thing. It's just that the way I learned to extract chakra is different from ordinary people. Maybe I can't help you much..."

"What's different?" Butterfly Ninja's eyes became more curious, "What's different? Do you have a better way?"

"Well... Zabuza-sama said that even if a human like me, who has the limit of synthetic blood successor, cannot extract chakra, his body will produce chakra independently with the explosion of blood successor."

Bai paused, as if he was ashamed of his special situation, and his expression was a little troubled when he spoke.

"As long as we can stay awake after awakening from the Blood Succession Limit, we will firmly remember the feeling of the body producing chakra independently for the first time. The ninjas in Kirigakure Village said that I took a shortcut, so this is not a big deal.

What’s a better way…”

If possible, he hoped he would never take this shortcut.

"The blood inheritance limit refers to your ability to make ice cubes yesterday?"

"Well, my blood inheritance limit is called Ice Escape, which I inherited from my mother." Bai lowered his head.

Butterfly held his index finger on his chin and thought.

She remembered that the history textbook said that the first Hokage, Senju Hashirama, mastered a type of blood inheritance called Wood Release.

Since she was resurrected using the cells of the first Hokage, in terms of genetic similarity, she should be closer to Senju Hashirama himself than the real Senju clan members. As the name suggests, the line of inheritance is based on blood, from generation to generation.

Special abilities passed down from generation to generation.

According to this reasoning, I should also have this blood inheritance limit called "Wood Release".

If you can learn how to extract chakra by relying on the blood successor to wake up like Shiro, you will definitely save a lot of trouble. Otherwise, you can only wait for Giyu to wake up and rely on his guidance.

Butterfly Ninja did not resist accepting help, but she was in late adolescence (at the time of her death), and she wanted to prove that she was not inferior to others. As a pillar, she didn't want to have the abilities that everyone knows as a ninja.

It can only be mastered with the help of volunteers.

"So Shiro," Butterfly Ninja asked, "What on earth does a person have to do to awaken the blood inheritance boundary?"

"..." Bai was silent for a while, and finally said slowly, word by word: "Although as we grow older, some signs will gradually appear. For example, when I was a child, I was not afraid of the cold, and the tea in my hand would cool down quickly.

…

"But only when encountering a life-and-death crisis, or a strong stimulus, and needing strength to protect yourself or vent, will the power of the Blood Inheritance Boundary truly explode."

This sentence reminds Butterfly Ninja of what Taketori Karashimochi once said——

In order for the children to awaken the ability called corpse veins, the Taketori clan will have them fight each other until they break each other's bones, thereby stimulating the body's potential for self-healing.

It can be seen that, to a certain extent, obtaining this kind of power that is different from ordinary people usually means that something bad has happened.

Although he didn't know what happened when Shiro's Blood Succession Limit was awakened, the Butterfly Ninja understood that by asking him like that just now, he was undoubtedly rubbing salt into Shiro's wound.

"Sorry for bringing up your sadness."

Butterfly Ninja apologized sincerely: "I crossed the line."

Then she added: "However, my sister used to say that if you keep bad memories in your heart, they will get moldy sooner or later. If you share your pain with someone, the weight in your heart will be reduced by half. If you want to talk
To be continued...