Fourth-grade basic Three Techniques, along with combat instruction between shinobi.
In reality, by the fourth grade, once students mastered The Three Techniques, they could apply for graduation. However, early graduation generally required passing all of The Three Techniques with flying colors, coupled with quite high requirements for past academic scores.
Due to the unique nature of the Ninja Academy—after all, everyone was destined for the battlefield in the future—the school did not explicitly encourage fighting, though it only managed things slightly more strictly during the first year; in practice, it didn't stop fights at all.
The only rule was that no severe injuries, permanent disabilities, or deaths could occur. Once discovered, punishment was bound to be severe, as these students would be of great use in the future and could not be pointlessly squandered within the school grounds.
Besides, even if you didn't go looking for trouble, could you survive without a social circle?
Once you had a social circle, could you avoid making friends?
And when your friends ran into trouble, could you back down?
If you backed down, wouldn't all that studying of the Will of Fire have gone to waste? How were you supposed to hold your head high in the future? This fully embodied that famous idiom: "In the pugilistic world, one's actions are often out of one's control."
Take today, for instance. Seven months into the new school year, Uchiha Chi, who had silently spectated plenty of drama from the sidelines, was wondering where he would go next to watch the show, never expecting that he would end up starring in it himself.
Uchiha Chi had to admit that even across lifetimes, he couldn't change the fact that he was an ordinary mortal. Watching drama was fun, but being the subject of the drama was not fun at all.
Although school had been in session for many days, the only people Uchiha Chi was truly familiar with in class remained his two desk mates. As for everyone else, they were mere strangers whose names he could recognize, but whom he didn't know at all.
Naturally, Sarutobi Shinnosuke played a part in this. In Uchiha Chi's eyes, that old brat was like a rat dropping that single-handedly ruined a whole pot of soup—or perhaps a fly that didn't bite, but was genuinely annoying. Day in and day out, he practically had "My dad is Lord Hokage" tattooed on his face.
Uchiha Chi even suspected that this whole incident was orchestrated by him; and even if it wasn't, his influence was certainly at play. The main reason was that Mizutani Hayun and Tachibana Taki came from humbler backgrounds and lacked recognition from their classmates, leading to frequent isolation.
Fortunately, the two girls huddled together for mutual support, and after spending time together later on, they discovered that Uchiha Chi was also a very easygoing person, not nearly as aloof as they had imagined. Thus, after a few days of getting along, the three of them could barely be considered friends.
Of course, by this time, Uchiha Chi was also gradually growing familiar with Inuzuka clan, Aburame clan, and Akimichi Xiu.
Moreover, since the first year focused primarily on mastering the Chakra Extraction Technique, and everyone in their class had already successfully extracted chakra, theoretical knowledge courses were relatively heavier, which naturally led to a corresponding increase in homework.
On this particular day, three students in the class who struggled with grasping academic knowledge were no longer satisfied with merely copying homework; in fact, they didn't want to do homework at all and just wanted to go out and play. After putting their heads together, they set their sights on the two girls.
Because these three boys were physically robust and had a numerical advantage, they cornered Uchiha Chi's two desk mates right after school let out, demanding that the girls help finish their homework for them. After failing in their resistance, the two little girls had no choice but to silently agree.
In the days that followed, although Uchiha Chi noticed a difference in the two—they appeared more fatigued than before—
he casually asked them a few times, but neither dared to speak up out of fear of retaliation. More importantly, Uchiha Chi's relationship with them could only be considered passable, far from particularly close, and they didn't believe Uchiha Chi would step up to help them.
Believing they were merely staying up late for extra training, Uchiha Chi didn't pry further, offering only a few words of concern. After all, having lived two lives without ever experiencing campus bullying, it simply hadn't crossed his mind.
It wasn't until one day, when an excessive amount of homework forced the two to spend a large portion of the night finishing it, that their condition the next morning plummeted to rock bottom. They fell asleep right in the middle of class and were caught by the teacher, even with Uchiha Chi trying to cover for them.
First, they were singled out and criticized by the teacher, then chased out of the classroom to stand in the corridor as punishment, bringing them to tears of grievance. Because Uchiha Chi had been covering for them, he was punished to stand out in the corridor as well.
The sense of grievance radiating from the two was so intense that Uchiha Chi finally woke up to their predicament, realizing that direct questioning would likely yield no answers.
While comforting them, he offered subtle guidance. With their emotions on the verge of collapse, the two accidentally let slip the truth, making Uchiha Chi realize that something was indeed wrong. He resolved to investigate after school and lend them a hand.
So when school ended, he declined to walk home with Uchiha Mikoto—who coincidentally needed to visit a friend's house, making things proceed smoothly.
He trailed the two girls the entire way and finally uncovered the truth. The three punks were currently threatening them to write even more homework, but the girls simply couldn't manage it. When soft pleas were met with total indifference, the boys resorted to threats.
As the punks adopted aggressive stances, threatening to turn to violence, the two girls ultimately broke down and yielded, reaching out to take the homework. Enraged by what he witnessed, Uchiha Chi transformed into an enforcer of justice and leaped right out.
First, he adopted a righteous tone to accuse the group: "You guys are going way too far! Bathed in the Will of Fire taught by Lord Hokage, as fellow classmates, you actually bully the weak—and little girls at that! Having classmates like you makes me, Uchiha Chi, feel deeply ashamed.
And on top of that, you're making others do the homework assigned by the teacher; you are simply defiling the Will of Fire. I'm going to report your vile deeds to the teacher so justice can be served."
Uchiha Chi first slapped a massive label on them to render his actions righteous, then threatened to report them to the teacher, making the boys lose their composure.
After all, at this age, a teacher's deterrence remained quite potent, especially since these few punks, despite coming from somewhat notable backgrounds, were small fry—otherwise, they wouldn't have stooped to becoming Sarutobi Shinnosuke's lackeys. He intentionally emphasized reporting to the teacher at the end, then pivoted away to deliberately tempt them into making a rash move.
Sure enough, the moment the boys saw Uchiha Chi's movement, panic set in. Desperate to stop Uchiha Chi first, they planned to figure out the rest later.
Seizing the momentum, Uchiha Chi let out a furious roar: "To cover up your own vile deeds, you actually intend to resort to violence against me? I, Uchiha Chi, am not someone to be pushed around! Take this!" He had originally wanted to say "In the name of justice, I shall punish you," but he felt too embarrassed to actually say it aloud.
Giving them no chance to speak, Uchiha Chi immediately deployed the ancestral craft of the Uchiha Clan—fighting fire with fire. In no time at all, he beat the entire group flat onto the ground, cleverly avoiding striking their faces.
Finally, with the group sprawled on the earth and ignoring their despairing gazes, he casually tore up every single homework booklet to deliberately blow the incident wide open.
It was worth mentioning that among these booklets were not only the homework of those few punks, but also those of several others—including a core lackey of Sarutobi Shinnosuke who belonged to the Sarutobi clan, which fueled Uchiha Chi's suspicion that the whole affair was engineered by him, even though solid evidence was lacking.