|| Flake-sensei was made an instructor pretty early on in his Jōnin career. What were the things he wished to carry over to his students from Jiraiya-sama's teachings and what were the lessons he would Katōn (twice over) rather than have his Genin Team learn the way he did.
Before I address the question, here’s a little disclaimer: Jiraiya was a highly respected Jōnin by the time he took Minato under his wing. As much as Minato idolized the man, he didn’t have the luxury of spending as much time with him as he would have liked; not only would the Gama Sage have enough missions to deal with, but he also had to divide his time between his students. Eventually, the Second Shinobi War kinda got in the way.
After the war, Jiraiya decided to get involved with the Ame orphans, much to a jealous blond teenager’s chagrin.
ANYWAYS - with regards to ‘pretty early’, we’re talking teenage years; post Second Shinobi War, because Konoha had lost enough shinobi during the conflict itself. What better way to teach young, talented children the art of murder than to assign them to equally talented soldiers who were…apt at the job, to say the least?
Enter one Namikaze Minato; one of Konoha’s rising stars. To say he was fairly young and inexperienced with squish-ables [an endearing term for Genin] is an understatement. In fact, when he was initially assigned said squishies, he was scared he would break them by accident [luckily said squishies happened to be a talented bunch; with Kakashi the genius chibi, Rin the super smart medic and Obito the Uchiha with a heart of gold]. His students were enough to melt the frigid shell that was the Yellow Flash.
And also scare the bejeebers out of him during numerous points because dang it they would bleed and bruise and he couldn’t help but worry.
The first lesson? Teamwork. Jiraiya tried to teach him that particular lesson well enough, as is evidenced by the numerous instances of Minato putting his students through the same exercise. Team Jiraiya had been dissolved around the Second Shinobi War - at least, for Minato it had, seeing as how he was promoted to chunin pretty early and sent off to an outpost - and he didn’t want the same fate to befall his poor students. Minato only got to experience the importance of teamwork because of his military experiences - a little too late, if you think about it.
Second lesson - Never underestimate your opponents. This may sound like a standard wack on the wrist with regards to Jōnin instructors and their students, but to Minato, it had been a rather rude awakening, since everyone loved to tell him how perfect he was [with the constant ‘you broke the Sandaime’s record you must be a genius’ or ‘the Sandaime’s own student is taking you under his wing’]. In fact, Kakashi’s case was basically a repeat of his own with the whole genius shtick. During the Third Shinobi War though, Minato would come to regret that he hadn’t taught them this particular lesson well enough.
Third lesson - Be kind. It sounds silly, coming from those who exchange lives/intel/possessions for ryō on a daily basis [aka your average shinobi/foot soldier]. However, everyone did what they did for a living and as such, their occupations [or their place around Hi no Kuni’s borders] should not breed malice - Jiraiya taught him that well enough, since the man would never speak ill of enemy or comrade.
Fourth lesson - Always take a wack at it. Jiraiya taught Minato the basics of form manipulation which is why he’s so skilled at what he does [and don’t think that didn’t involve the ‘if I throw the brat into a river he’ll learn to swim by himself’ approach to a degree XD]. As someone who was always experimenting with ninjutsu and of the like, Minato had wanted to instill the same curiosity and sense of exploration in his students via gentle prodding and encouragement.
The lessons he would incinerate twice over with a nifty Katōn no jutsu though? Probably the social skills or lack thereof. Jiraiya, as amazing as he was, was prone to attracting the ire that revolved around his extracurricular activities. Where do you think Minato gets his lack of social skills from? Add in the Three Shinobi Vices [which his sensei more or less kicked out the proverbial window].
That…and false promises [enter the fact that he couldn’t help Kakashi deal with the loss of his teammates]. The sage never did return to Konoha after the Second Shinobi War. Minato couldn’t bear the guilt of promising his students a future, or give them hope when it didn’t exist - at least, not in the same capacity as Jiraiya had instilled. But then again, maybe it was Minato’s fault for attributing certain expectations to a man who had a bigger picture in mind.
P.s. This is colored by the fact that Minato still thinks Jiraiya is the best shinobi ever. ._.
