As Jin carries Jiraya in tow the academy gates start to open and everyone is led into one of the classrooms where everyone finds a place to sit, Orochimaru is the only one that is sitting alone at his table meanwhile Tsunade can barely be left alone by her fans. Jin takes Jiraya to his usual spot to the back of the classroom closest to the window. Jiraya notices this as they pass by several empty places before sitting down at the back and starts to wonder why Jin choose this place and asks him.
"Jin, why are we sitting here, at the back of the classroom? We just passed several empty spots that are much closer to the teacher."
Hearing this Jin puts on a serious face and leans his face closer to Jiraya and starts to whisper. Jiraiya seeing this change is confused but still humours him and leans his face closer as well.
"Jiraya, I'm going to be very serious now, since your both my friend and brother now I don't want anything to happen to you so pay close attention," Jin whispers slowly and making sure to punctuate every word to make sure Jiraya is listening.
Jiraya hearing this warms his heart a little even though he considers Jin a little bit crazy from all his antics, he makes sure to listen closely. Jin then continues to tell his lesson to Jiraya.
"Let me give you a piece of advice, always be on guard. Whether your eating, sleeping or even taking a shit, always be on guard. When we graduate and become gennin we will start to take on missions, and the shinobi world is ruthless and cruel to the point that even the easiest of missions might turn out to be life-threatening. Only the cautious and strong survive and if you lose focus or drop your guard even for a second you or someone you care about may drop dead."
Jiraya hearing this is slightly shaken and taken aback as even though he is not the most cautious person, he always considered himself as such as it was a necessary mindset while growing up in an orphanage with no one but himself to rely upon. Though even he considers Jin's advice as borderline delusional, but seeing Jin's serious face and the conviction in his eyes convinces Jiraya. That although his advice sounds delusional and crazy, it's still better to listen to it than end up dead.
As Jiraya slowly nods the teacher then comes in and starts to ramble on the rules of the academy and what they will start learning, mostly stuff that isn't too important to listen to as it's still the first day of the academy. And as such Jin tunes out the teachers rambling and reminisces about his new life in the Naruto universe. He remembers how confused and excited he was in the beginning, being born in one of his most favourite fictional universes, but then grew increasingly depressed later on knowing how dangerous and wartorn the universe is. He decided then and there to become as strong as he can. Not just because he can and to survive, but also to fulfil his childish dreams no matter how hard or impossible they may seem at first.
His training consisted of mostly training his body and focusing on taijutsu first since he couldn't unlock his chakra early on. Also knowing that a lot of enemies like to use poisons, he decides to start building his poison resistance early on in secret. He did that by reading in most of his spare time when he was resting from his training, making him quite knowledgeable in many various subjects such as the human body, poisons, taijutsu techniques as well as kenjutsu. Unfortunately, ninjutsu are unavailable until you reach at least gennin class first so he decided to put that on for later and instead focus on training his chakra itself.
Later on, when his chakra was unlocked he used his chakra in almost everything he did. If he could do something with chakra instead of using his body he would do it in a discreet way. Jin also trained in all of the chakra training techniques that he can remember from the series as well as a few he learned by reading for good measure. All of Jins training has shown results albeit very slow results as his body is still developing and he is the first shinobi in his family. This has led to him being a high-level gennin already just before starting the academy.
(Even though I'm a high-level genin class in terms of chakra volume and taijutsu, my ninjutsu is still piss poor as most ninjutsu are sectioned off for gennin and higher class shinobi. It's a good way to protect against any spies hidden among the students but it's a very big detriment to me as I'm very far behind the kids of the big clans and shinobi families.)
(I did try to emulate the jutsus that I can remember from the series like Chidori and the Rasengan, yet I've had very little success there as both the Rasengan and Chidori requires way too much chakra to the point that I can only fire off 1 of each before I'm completely out of chakra, useful in a life or death situation but useless other times as they leave you right open to attacks if you miss or don't do enough damage. That just shows the vast distance between me and the 2 monsters of the series, Naruto and Sasuke. Even in the series apart from only those 2, everyone else who used those jutsus was high level jonnin class.)
As Jin was in his thoughts the teacher noticed this and raised his voice and said: "It seems like Goto-San isn't interested in my class and thinks he knows everything already, for that you will stay behind alongside your friend there and clean up the old archives room."
Hearing this Jiraya wanted to refute yet in the end he had no choice but to accompany Jin in his punishment. Jin seeing this grew grumpy and pouty yet he couldn't but help a smile form on his face.
(Mwhahahah, all according to keikaku/plan, the old archives might contain a hidden gem or two and who I'm a to refuse such easy loot.)
Once class ended Jin and Jiraya were brought outside the old archives room and when they looked inside they almost thought they were brought to the wrong room as it looked more like a trash room than anything else. Nonetheless, that didn't stop Jin's enthusiasm in trying to find his hidden gems. But as time went on Jin started to lose hope as all he could find were old records and historical archives. Eventually, near the end of their detention, Jin picked up a stack of papers when 2 scrolls dropdown. As Jin was bending down to pick them up he noticed that they looked a bit old, not too much but enough to notice their age. Growing curious and holding on to his dwindling hope he opened them up and his eyes almost popped out from his sockets realizing what they were.
(These are the best-hidden gems I could ever find.) Snickers Jin evilly to himself.
What do you think he found? Comment it and let me know. As you can see the story will be a bit slower as I want to properly expand Jin and his actions as well as his relationship with the sannin. Cheers, and hope you enjoy it!