Naruto: I start with one door, and I can open it infinitely.

One week later, in the Death Forest.

Lin Chuan had become accustomed to the rhythm of life in the Death Forest. He dug a cave on the cliff by the river in the Death Forest, which could be considered a form of cultivation.

It took him a week just to dig out a cave big enough for him to sleep in, and he also found a bunch of licorice to put on the stone bed.

The Death Forest is home to many ferocious beasts, which are either eating other animals or being eaten by other animals. The most common ferocious beast he has encountered is the wild boar.

The wild boar, which is two to three meters long and nearly two meters tall, is also a tyrant in the Death Forest. He dares not provoke it. Don't underestimate the boar. This thing is an omnivore and can eat meat if there is meat available.

Seeing that the Roots had not summoned him back, he settled down in the Death Forest. Rather than staying in the oppressive Roots, he preferred to be alone in the forest, where he only needed to report to the Roots once a week.

These children recruited into Root by Danzo were not as strict as the adult ninjas, nor did they have any missions to complete. As they were only genin, they were not capable of carrying out missions.

After a quick wash, gazing at the rising sun in the distance, he began his day's training in the cave, starting with refining chakra.

Now that he doesn't have to go to school, he has a lot more time for cultivation. However, he has to find his own food. Fortunately, he can apply for a batch of soldier ration pills every week. When he's too lazy to find food, he can just swallow the soldier ration pills. They just don't taste very good, but they are very filling.

After refining his chakra, he went to the edge of the cliff and began rock climbing. He had seen Kakashi, Guy, and other taijutsu masters in the anime train in rock climbing, so he started training with them.

After training for a while, he discovered that rock climbing can enhance muscle strength and endurance. Rock climbing requires the coordinated exertion of all muscle groups, especially the arms, back, core, and legs, which can effectively improve muscle strength, endurance, and explosive power.

It can also improve coordination, balance and flexibility. Rock climbing requires the use of both hands and feet and stability on the rock face, which can significantly improve the body's coordination, balance and joint flexibility.

It greatly helped him in using ninjutsu and training his taijutsu. Since arriving in the Forest of Death, he has climbed the cliff once every morning and afternoon.

After successfully climbing to the top of the cliff, he climbed down and went to the river to get a fish and a piece of dried meat to prepare lunch. The grilled fish was just for appetizers, while the soldier's ration pills were the main meal. He would take one of these pills with each meal to make up for the lack of carbohydrates and the consumption of chakra.

After lunch, he went into the forest with his load and equipment, looking for a wild boar of a size he could handle.

Then throw kunai at the wild boar. If you can kill it, great, and make it into jerky for a snack. If you can't kill it, it can still serve as a sparring partner.

He combined kunai throwing with weighted jogging, replacing moving target practice with throwing kunai at wild boars, and weighted jogging with dodging wild boar attacks.

After finding the wild boar from yesterday in the tree, he took out a kunai from his ninja tool bag and threw it directly at the boar.

whoosh-

At this moment, the wild boar was still happily turning over the soil, searching for food in the mud, when suddenly a kunai was stuck in its rear end, and it immediately let out a howling sound.

Awooo, awooo—

Lin Chuan also jumped down under the tree and caught the kunai that the wild boar had knocked off. What followed was a fun time of chasing each other.

He needs to use kunai to hit the wild boar he's chasing while moving, and also dodge the boar's attacks, to practice his dodging skills.

"Snoring, snoring," the wild boar saw a person suddenly appear in front of it, and when it thought of the knife in its buttocks, its eyes instantly turned red.

Enemies meeting are bound to be furious. This isn't the first time it's been pricked in the butt. This two-legged creature has successfully enraged it, and watch as it charges like a wild boar.

Rumble, rumble—

A one-meter-long wild boar isn't very big, but when it runs, it still shakes the ground. Especially since the person facing the wild boar was just a seven-year-old child, Lin Chuan immediately took off running without even thinking of throwing his kunai.

After he led the wild boar for a stroll in the forest and they arrived at an open riverbank, he took out a kunai and threw it at the boar, which immediately made the boar squeal loudly.

This is the second wild boar he found for sparring this week. The first wild boar was too small and he killed it in just three days, then hung it in the cave and made it into jerky.

"Awooo, awooo!" The wild boar had gone mad, completely ignoring the kunai on its body, and only knew how to charge at Lin Chuan.

It was this loss of reason that gave Lin Chuan the opportunity to kite the wild boar, slowly wearing it down to death—a wild boar that weighed four or five times his own weight.

Unfortunately, even wild boars eventually give up. As their anger subsided and their intelligence regained its advantage, the boar glanced at Lin Chuan, who was also panting heavily but whom it still couldn't reach, and then turned and returned to the forest.

Watching the wild boar disappear into the distance, Lin Chuan did not chase after it. He was not yet capable of confronting a wild boar head-on, and he was still far from being able to defeat it without taking any damage. When he could defeat a wild boar without injury, that would be the time for him to start hunting.

He went to the river, took off his clothes and took a shower. He hung his sweat-soaked clothes in the water to wash them. He also prepared dinner, which was just simple roasted dried meat and soldier's rations.

Then, after putting on his dried clothes, he returned to his cave and quietly ate his dinner. After dinner, he created a shadow clone and gave most of his chakra to it, sending it to the river to train in ninjutsu.

Once the shadow clone's chakra was exhausted, the shadow clone disappeared, and his memories returned to Lin Chuan, his day's training was over.

During this period, he mainly trained his shadow clones in the Body Flicker Technique, and used the remaining chakra to learn the Water Release: Heaven's Cry, a B-rank ninjutsu. He had to learn this ninjutsu before going on a mission, as it was his only means of survival.

After a week of experimentation, he has made some progress and knows how to compress high-density water injections in his mouth, but the power of the spit-out injections is insufficient.

As we all know, when eating watermelon, the human mouth can also be a launcher. It needs to give the high-density water needles a super-fast initial velocity in the mouth for the water needles to have power and penetrating force.

This might require the assistance of chakra. How to deliver a high-density water needle at high speed in a space the size of the mouth is not described in the ninjutsu scroll. This ninjutsu may only have been used by the Second Hokage.

He also knew of a certain ninja, Genma Shiranui, who could spit out senbon, which is a single toothpick. However, he could not see the ninja and could not learn his technique. But the ability to launch senbon was probably related to chakra.

However, he has another way to increase the initial velocity of high-density water jets, which is a negative pressure state. The greater the negative pressure, the faster the flow rate. This is just one of the methods.

If the acceleration of the high-density water jet is increased, then the initial velocity of the high-density water jet will be even faster.

Speed ​​equals penetrating power. As long as the high-density water needles have enough acceleration, penetrating Susanoo is not a dream.

Unfortunately, his mouth is too small. Even if he makes the acceleration spiral, his mouth can't accommodate many rotations unless he can insert the acceleration of the high-density water needle into his body, in which case the penetrating power of the water needle might be greater.

However, this would consume more chakra. He might as well increase the initial velocity of the water needles, which would be much faster than increasing their acceleration and would also save on chakra consumption.

The initial velocity only needs to be addressed.

Acceleration also requires water injection to construct a spiral-structured chakra negative pressure acceleration channel.

Just by looking at the names, you can tell which one is more complicated. He'll start with the simpler one first. He can figure out the more complicated negative pressure acceleration pipes later when he has time. After all, he doesn't need to face enemies who can use Susanoo right now.

This is his training routine for the day, as monotonous and boring as ever. He also has to do math problems, which is really a headache. I never thought that I would have to calculate negative pressure even though I don't have to go to school. Fortunately, I didn't miss my math class.