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

With Lin Chuan's mother gone, Maruhoshi Kosuke no longer refused. He picked up the teacup on the table and was about to take a sip when he saw Lin Chuan forming a hand seal by the pond. The hand seal Lin Chuan was forming was the Water Dragon Bullet seal, and Maruhoshi Kosuke was very familiar with the sequence of the hand seal.

At this moment, Lin Chuan had already noticed the arrival of Maruboshi Kosuke. In fact, after receiving the notification from his father, he had been preparing to use the Water Dragon Bullet for the past two days until Maruboshi Kosuke arrived.

However, since he hadn't used chakra in his previous practice, when he saw Maruboshi Kosuke appear under the eaves, his hand seals immediately changed from empty seals to seals that mobilized chakra.

Until all forty-four hand seals were completed perfectly, the movements were slower and more precise than ever before, all for the sake of successfully releasing the Water Dragon Bullet in one go. Immediately, he shouted, "Water Release: Water Dragon Bullet..."

With a loud shout, the stagnant water in the pond instantly surged, and a huge, ferocious dragon head emerged, with two orange-yellow dragon eyes that looked like a pair of large lanterns. Then, the dragon's body, formed by the flow of water, slowly emerged, along with its four limbs and claws that were bared and menacing.

Only when the dragon's head and body rose high into the sky did it open its large mouth with sharp teeth and crash into a large tree not far away.

Rumbling--

The dragon bit down on the thick tree trunk, and with a crack, the trunk split open. Then, the water rushing over the dragon's body snapped the trunk in two, and the dragon rushed towards the river not far away.

Seeing the water dragon bullet snap a large tree in two, Maruhoshi Kosuke, who had been holding a teacup, forgot to bring it to his lips. His mouth was slightly open, and he remained speechless for a long time, muttering to himself, "Water dragon bullet, it really is a water dragon bullet..."

"How is this possible?" Maruboshi Kosuke was still incredulous. That was just a child. How could he use the B-rank ninjutsu, Water Dragon Bullet? Was he seeing things? Could this child be a genius?

He instantly felt that the herbal tea in his hand no longer tasted good. As he put down the herbal tea, he used a teleportation technique to appear next to Lin Chuan, who was somewhat exhausted.

Lin Chuan's exhaustion was just an illusion. He still had half a B-rank ninjutsu's worth of chakra left. If he didn't show that he was expending a lot of energy, it would be too inconsistent with his age and his competitive spirit of blindly rushing to train in advanced ninjutsu.

"Child, how old are you?" Maruhoshi Kosuke asked, looking at Lin Chuan, who was kneeling on one knee and panting heavily.

"Who are you?" Lin Chuan pretended not to recognize Maruboshi Kosuke, but still answered him, "Grandpa, I'm six years old, I'll be seven next semester..."

"What? Only six years old? What kind of Water Dragon Bullet are you using? Don't you know that's a B-rank ninjutsu? There's danger in forcibly training it?" Maruhoshi Kosuke was shocked when he heard that the child was only six years old. This child's performance was simply too astonishing.

"I know, I didn't force myself to train," Lin Chuan said, his mouth dry from panting. He swallowed hard before continuing, "I've already learned Water Clone, Water Wave, and Water Barrier. Water Dragon Bullet is the fourth ninjutsu I've learned. I learned Water Dragon Bullet after gaining experience from learning B-rank ninjutsu..."

"You've already learned four ninjutsu...?" Maruboshi Kosuke was speechless for a moment. He thought Lin Chuan would learn Water Dragon Bullet right away, but he didn't expect that he learned Water Dragon Bullet because he had the experience of the prerequisite ninjutsu.

Suddenly, he remembered that when he was chatting with Lin Chuan's father before accepting the mission, Lin Chuan's father had mentioned that his son had learned ninjutsu.

At the time, he didn't pay much attention, thinking that it was just a father showing off his child and comparing his child's academic performance with those of other prominent families. But Lin Chuan's family wasn't one of those big families.

Now that he has witnessed Lin Chuan using the Water Dragon Bullet, he has no choice but to believe it. He finally understands what kind of child the genius Lin Chuan's father spoke of is, who may be no less talented than those genius children cultivated by their families.

"It's still a bit of a stretch. With my chakra reserves, I'll lose the ability to fight after using this ninjutsu. It seems I can't use it in battle," Lin Chuan slowly stood up and muttered to himself. Seeing the tea under the eaves, he decided to go back and have a cup of cool tea.

After he poured the iced tea, and Maruhoshi Kosuke approached, he sipped the tea while muttering to himself, "If only I had a teacher, it would be so much better. It's too slow to learn ninjutsu all by myself..."

"What? This kid doesn't have a teacher, he's self-taught?" Maruhoshi Kosuke was shocked again when he heard Lin Chuan's whispered words. This was no longer just a genius.

Without any instruction, he actually learned four water-style ninjutsu, including the Water Dragon Bullet with forty-four hand seals. He remembered that even Lin Chuan's father hadn't learned this ninjutsu before retiring due to injury.

At the time, seeing how hard Lin Chuan's father worked to learn the Water Dragon Bullet technique and even asked him for tips, he had the idea of ​​teaching Lin Chuan's father a simplified version of the Water Dragon Bullet ninjutsu. However, after hearing that the other party had retired due to injury, the idea was abandoned.

"Grandpa, who are you?" Lin Chuan asked Maruboshi Kosuke again after putting down his teacup as he approached.

"I am Maruboshi Kosuke. You should have heard your father mention me, right?" Maruboshi Kosuke smiled as he looked at Lin Chuan, as if he were looking at a precious gem, suddenly recalling his past self.

"Maruboshi Kosuke? You're Grandpa Maruboshi Kosuke?" Upon hearing Maruboshi Kosuke's name, Lin Chuan's expression instantly became extremely excited, his eyes sparkling. He excitedly asked, "Grandpa Kosuke, my father told me you're a powerful ninja. Can you teach me ninjutsu?"

Children don't need to beat around the bush; children speak without restraint. When they see a powerful ninja elder, they can just follow him and learn from him.

"Ahem," Maruhoshi Kosuke saw Lin Chuan's admiring gaze, subconsciously averted his eyes, raised his hand to his mouth and coughed dryly, pretending to be reserved.

Actually, he was secretly overjoyed. He was totally swayed by this. He hadn't expected the child to look down on him just because he was a low-ranking ninja. It seemed that Lin Chuan's father had done a good job with his upbringing and family values. That's how you should treat your elders.

"Well, well," Maruboshi Kosuke hesitated. His ninjutsu was inherited from the Second and Third Hokage. Would it be a bad idea to just hand it over to a child like this?

"Grandpa Kosuke, please teach me, Grandpa Kosuke," Lin Chuan saw that Maruhoshi Kosuke was starting to hesitate, and he immediately thought that he had a chance. He immediately used the trick that children usually use, the trick of acting cute. This trick always worked on these older people who cherished talent.

At this crucial moment, neither Lin Chuan's mother nor his father came to disturb them. They had already discussed that if Lin Chuan couldn't handle Maruhoshi Kosuke, they would implement Plan B, having the elderly couple cooperate.

"Alright, alright, Grandpa will teach you," Maruhoshi Kosuke finally succumbed to the repeated calls of "Grandpa." After all, he was already nearing seventy and still all alone. Having a child call him "Grandpa" was incredibly powerful.

"Yay! Grandpa taught me ninjutsu, so he's my master now!" Lin Chuan blurted out, regardless of whether Maruboshi Kosuke acknowledged him as a disciple or not, he had already decided that Maruboshi Kosuke was his teacher.

"Haha, alright, alright, I'll teach you ninjutsu." Maruboshi Kosuke showed no aversion or even refusal to be addressed as "Master." Who wouldn't be tempted by such a young genius?

He was a disciple of the Second Hokage, and he was getting old. If he hadn't been unable to find a suitable disciple, he wouldn't have wanted to take the Second Hokage's ninjutsu to the grave.

Since he had run into him here, and it was his old friend's son who was so polite to him, and most importantly, he called him grandpa, he really adored this grandson.

"Grandpa, Grandpa, quickly teach me ninjutsu!" Lin Chuan hurriedly pulled Maruhoshi Kosuke to the poolside, excitedly asking, "Grandpa, what ninjutsu do you know? What ninjutsu will you teach me?"

"Ogawa, I just heard you say that you've already learned Water Wall and Water Dragon Bullet. I'll teach you those two ninjutsu," Maruboshi Kosuke said with a smile, looking at Lin Chuan, wanting to know how Lin Chuan would react.

"Huh? Water Wall and Water Dragon Bullet? I've already learned both of those ninjutsu," Lin Chuan said, showing the disappointment a child should have. His excited expression instantly vanished, which was a normal reaction for a child.

"Hahaha," Maruhoshi Kosuke couldn't help but laugh when he saw this scene. He really is just a child.

He stopped teasing Lin Chuan and immediately explained, "Little Chuan, the ninjutsu Grandpa is going to teach you is no ordinary technique. Your Water Dragon Bullet has forty-four hand seals, while Grandpa's only has six!"

"What? Six-marked water dragon bullets? How is that possible?" Lin Chuan looked surprised again, finding it hard to believe that such superb acting skills could appear in a child.

"Watch closely, Grandpa will demonstrate for you now," Maruboshi Kosuke said, slowly forming six hand seals in front of the pond: Rat-Ox-Tiger-Snake-Horse-Rooster. He finished the seals and shouted sharply, "Water Release: Water Dragon Bullet..."

Rumbling--

A dragon's roar resounded, snapping another large tree in half. It was even more powerful and fierce than Lin Chuan's water dragon bullets, and its momentum was unstoppable.

"This? That's amazing! I want to learn this!" Lin Chuan's eyes sparkled again. This time it wasn't an act; he genuinely wanted to learn the simplified version of the water dragon bullet. Otherwise, with forty-four water dragon bullets, even a dog wouldn't need them...

"Hahaha, watch closely, the simplified hand seals for this ninjutsu are..."

"I've learned it," Lin Chuan said, having already memorized the six seals before Maruhoshi Kosuke could demonstrate again.

Since the goal is to portray a genius, a good memory is essential. When Maruboshi Kosuke was forming hand seals, his eyes were fixed on Maruboshi Kosuke's hands. He didn't even pay attention to the Water Dragon Bullet attack just now, but was focused on memorizing the sequence of hand seals.

Unfortunately, he wasn't a genius to begin with. To memorize the hand seal sequence of a ninjutsu instantly, he had to abandon all distractions and focus all his energy on memorizing the sequence.

Fortunately, the simplified version of the Water Dragon Bullet only had six seals, and he managed to memorize them by rote. He immediately went to the pond and slowly formed the seals.

When the six hand seals were successfully completed, and the ninjutsu was used by mobilizing the chakra in the body according to the hand seal method of the Water Dragon Bullet of the Forty-Four Seals, the water in the pond instantly boiled and surged. However, as soon as the Water Dragon Bullet emerged with a dragon head, it went limp again, splashing up a huge spray of water.

"Damn it, I don't have enough chakra!" Lin Chuan was so excited that he forgot he didn't have enough chakra to release another Water Dragon Bullet, and in the end, he could only release the ninjutsu and it failed.

"Don't worry, you've already succeeded, you just don't have enough chakra," Maruboshi Kosuke said. He was instantly thrilled when he saw the dragon head rise in the pond, but he breathed a sigh of relief when he saw it fall back down.

He then remembered that Lin Chuan had already used the water dragon bullet once, and he definitely couldn't use it a second time. However, the dragon head of the water dragon bullet had already risen from the water surface, and it was an indisputable fact that the child had learned the simplified version of the water dragon bullet.

"Phew, what a genius! He learned it after just one look," Maruboshi Kosuke smiled with satisfaction, overjoyed to have such an outstanding disciple.

But it was precisely because his disciple was so talented that he began to feel afraid. He was afraid that he would not be able to teach such an outstanding disciple well. After all, he was just a genin and there was still a gap between him and those jonin who had been famous for a long time. He was afraid of delaying the child's progress and was also afraid that a genin teacher would bring bad rumors to the child.

However, Lin Chuan was unaware of Maruboshi Kosuke's complex thoughts at that moment. He was short of chakra and could only stop forming hand seals, take out his notebook to write down the sequence of the hand seals he had just formed, otherwise he would forget them later.

As for the fact that he was able to learn the simplified version of the Water Dragon Bullet in one go, there was nothing strange about it. Before meeting Maruboshi Kosuke, he had already used the Water Dragon Bullet more than ten times.

Having become familiar with the chakra manipulation method of the Water Dragon Bullet ninjutsu, and combining it with a simplified hand seal method, it's like adding wings to a tiger.

"Grandpa, what about the Water Formation Wall? Is there a simplified version of the Water Formation Wall?" After recording the hand seal sequence of the simplified version of the Water Dragon Bullet, Lin Chuan looked at Maruhoshi Kosuke with wide eyes, waiting for the other party to continue feeding him.

"Yes, there's also a simplified version of the water array wall, with only two seals: Yin and Si," Maruhoshi Kosuke demonstrated it to Lin Chuan again. A pillar-shaped water wall instantly rose from the pool. After the water wall landed, he looked at Lin Chuan and smiled, "Got it? Chuan-kun..."

"I've got it, Grandpa," Lin Chuan said, glancing at the simplified water array hand seal sequence in his notebook. He then put the notebook away and smiled at Maruhoshi Kosuke, "Grandpa, my old man's back..."

"Is that so?" Maruhoshi Kosuke turned around and looked under the eaves. A middle-aged man was standing there, smiling and waving at them. He immediately called Lin Chuan back: "Let's go, Lin Chuan, let's try again another day..."

"Okay," Lin Chuan didn't plan to try it now. He didn't have a drop of chakra left, only a little bit for survival. He didn't dare to use it recklessly. He would wait until his chakra recovered tomorrow before trying out the simplified hand seal method of the array wall.

"Senior Kosuke, how's this brat? Did he disturb your tea?" Lin Chuan's father glanced at Lin Chuan out of the corner of his eye and saw Lin Chuan blink slightly. He knew that things had gone well, and it was the best possible outcome. His smile widened.

"No, no, Ogawa is very good," Maruhoshi Kosuke was very satisfied with Lin Chuan's performance and was very pleased with this disciple. Now he was worried that his disciple was too outstanding and that he would have nothing left to teach in the future.

"Haha, come on, come on, Mom has prepared the food, let's go have a drink first," Lin Chuan's father no longer cared about what had just happened, as long as things went well, he quickly pulled Maruhoshi Kosuke to the kitchen to eat.

Lin Chuan followed closely behind the two, and went to the kitchen to serve them rice. As for how to pour the wine, that was up to the two of them.

After Lin Chuan's father got drunk, he cried to Maruhoshi Kosuke, saying that Lin Chuan was too sensible and he didn't want them to worry. But Lin Chuan was too smart, and he could no longer teach him any ninjutsu. He was just an ordinary Chunin and couldn't find a good teacher.

That's why we asked Maruboshi Kosuke to see if he could take Lin Chuan in and guide his cultivation.

Faced with Lin Chuan's father's tearful complaints, Maruboshi Kosuke was also somewhat helpless. He was initially delighted to see Lin Chuan, never expecting to encounter a genius disciple in the field of water-style techniques.

After teaching Lin Chuan two ninja techniques, he realized that having a disciple who was too talented was not a good thing. He had only shown his skills twice, and Lin Chuan had already learned them. What would happen in the future? Sooner or later, he would run out of things to teach.

I only know a few ninjutsu techniques. Once I've taught them all, I won't have anything left to pass on to Lin Chuan. I don't know if Lin Chuan will still acknowledge me as his teacher.

Maruboshi Kosuke was unaware that his identity was far more important than any number of ninjutsu. With the kinship of being fellow disciples with Sarutobi Ryouden, Lin Chuan was also a ninja from the Hokage lineage, and he could have some connections with people from the Hokage lineage.

When he encounters Jiraiya, he can still call him "senior brother," and Naruto and Sasuke will have to call him "uncle-master." This is a win-win situation, gaining both substance and prestige.

While Naruto and Sasuke are still young, I can beat them to a pulp and make them call me "daddy." It's so satisfying! I can bully these two even before I reach Chunin level. Just thinking about it is so cool!