I think it's interesting how much we still don't actually know of the past of Gintama, how much Sorachi leaves open or merely lightly implied.
Going to try to get into it here, behind the cut. Beware of spoilers up through the final story arc (but nothing beyond what's been animated). I would very much love to get comments!
So we know that Shoyo picked up Gintoki from the battlefield. An unspecified time later, I'm guessing several years, they reach the town (village?) where Katsura and Takasugi live and attend a prestigious military training school for elite sons of samurai. Shoyo establishes a temple school where everyone can attend for free, where he teaches writing and swordsmanship. (It's never explained where he gets the funds for this. Maybe the community lets him have the building in exchange for letting any child attend, but what about food and other necessary living expenses for himself and Gintoki? Firewood to heat the building? Other upkeep for school and kendo hall? Etc.)
Takasugi starts to challenge the champion of the temple school in the kendo hall, that is to say Gintoki, in the hope of getting to fight Shoyo. Shoyo talks to him after he loses and passes out, giving young Takasugi a new perspective of what it might mean to become a samurai. Katsura is seen peeking on Takasugi's fights and eavesdropping on his conversation with Shoyo. Takasugi keeps challenging Gintoki and loses, until eventually he manages to win, after which the other students compliment him, Shoyo tells him he's been showing greater fervour than anyone else to train there, as if he was a student himself, and Katsura turns up out of nowhere and starts making rice balls. Gintoki tells Takasugi he'd better keep coming back so they can keep fighting.
All seems well...!
But then there's rumours that Shoyo is spreading anti-government sentiments in the school, and Katsura and Takasugi gets told by those same older would-be bullies from before that the school will be destroyed. [It doesn't say "burned" in the translation, only "destroyed", so I'm not sure if this means a literal destruction of the building or not.] Takasugi beats up those teenagers and Katsura goes to the temple school to warn everyone, then both of them intend to confront the government officials coming to destroy the school and arrest Shoyo. Gintoki turns up and tells them he'll take care of this, but the other two refuse to back down and declare they've had enough of their old school and old life anyway.
Then Shoyo shows up, cuts through the officials' swords without anyone even seeing him draw his own, tells them not to point their swords at their students, so the officials run away. He says to Katsura and Takasugi that he doesn't have a school left to welcome them into, but they insist they want to follow him anyway. (Katsura says "as long as you're there, even a field or some farmland is a school".) So then Shoyo accepts them into Shoka Sonjuku for real. Presumably, they all leave the town that same night. (Maybe Katsura might have run home again quickly to pack some things, considering he lived alone so nobody would catch him at it.)
I've always read that final scene to imply that after that, Shoyo and the other three spent some time wandering, perhaps temporarily stopping at some villages for weeks or months and opening a school there only to move on later. However, we don't see anything of that wandering: for all we know they might have found a new permanent place fairly quickly.
The other flashback scenes we see of Shoka Sonjuku, whether from Benizakura arc (classroom), Courtesan of a Nation arc (outside the now-burning building), or Battle of Rakuyo arc (kendo hall), might all be from the same physical school - the one that the Naraku set on fire at the end as Shoyo is arrested as part of the Kansei purge, which the shogun Sadasada ordered on the instructions of the Tendoshu.
This is the school whose charred ruins Takasugi eventually returns to in order to bury Oboro's ashes there, the physical place evoked in nostalgic memories by him, Gintoki and Zura.
But we never get to know anything about how long a time Shoyo and the boys were there, if it was far from the military training school or not, if they had to spend a long time wandering before getting there, etc. A popular conjecture, understandably, is to place it in Hagi where the historical Shoka Sonjuku academy was run by the historical Shoin Yoshida. However, as far as I know the Gintama manga contains no hint of its geographical setting, except that it's very much in the countryside.
Going to try to get into it here, behind the cut. Beware of spoilers up through the final story arc (but nothing beyond what's been animated). I would very much love to get comments!
So we know that Shoyo picked up Gintoki from the battlefield. An unspecified time later, I'm guessing several years, they reach the town (village?) where Katsura and Takasugi live and attend a prestigious military training school for elite sons of samurai. Shoyo establishes a temple school where everyone can attend for free, where he teaches writing and swordsmanship. (It's never explained where he gets the funds for this. Maybe the community lets him have the building in exchange for letting any child attend, but what about food and other necessary living expenses for himself and Gintoki? Firewood to heat the building? Other upkeep for school and kendo hall? Etc.)
Takasugi starts to challenge the champion of the temple school in the kendo hall, that is to say Gintoki, in the hope of getting to fight Shoyo. Shoyo talks to him after he loses and passes out, giving young Takasugi a new perspective of what it might mean to become a samurai. Katsura is seen peeking on Takasugi's fights and eavesdropping on his conversation with Shoyo. Takasugi keeps challenging Gintoki and loses, until eventually he manages to win, after which the other students compliment him, Shoyo tells him he's been showing greater fervour than anyone else to train there, as if he was a student himself, and Katsura turns up out of nowhere and starts making rice balls. Gintoki tells Takasugi he'd better keep coming back so they can keep fighting.
All seems well...!
But then there's rumours that Shoyo is spreading anti-government sentiments in the school, and Katsura and Takasugi gets told by those same older would-be bullies from before that the school will be destroyed. [It doesn't say "burned" in the translation, only "destroyed", so I'm not sure if this means a literal destruction of the building or not.] Takasugi beats up those teenagers and Katsura goes to the temple school to warn everyone, then both of them intend to confront the government officials coming to destroy the school and arrest Shoyo. Gintoki turns up and tells them he'll take care of this, but the other two refuse to back down and declare they've had enough of their old school and old life anyway.
Then Shoyo shows up, cuts through the officials' swords without anyone even seeing him draw his own, tells them not to point their swords at their students, so the officials run away. He says to Katsura and Takasugi that he doesn't have a school left to welcome them into, but they insist they want to follow him anyway. (Katsura says "as long as you're there, even a field or some farmland is a school".) So then Shoyo accepts them into Shoka Sonjuku for real. Presumably, they all leave the town that same night. (Maybe Katsura might have run home again quickly to pack some things, considering he lived alone so nobody would catch him at it.)
I've always read that final scene to imply that after that, Shoyo and the other three spent some time wandering, perhaps temporarily stopping at some villages for weeks or months and opening a school there only to move on later. However, we don't see anything of that wandering: for all we know they might have found a new permanent place fairly quickly.
The other flashback scenes we see of Shoka Sonjuku, whether from Benizakura arc (classroom), Courtesan of a Nation arc (outside the now-burning building), or Battle of Rakuyo arc (kendo hall), might all be from the same physical school - the one that the Naraku set on fire at the end as Shoyo is arrested as part of the Kansei purge, which the shogun Sadasada ordered on the instructions of the Tendoshu.
This is the school whose charred ruins Takasugi eventually returns to in order to bury Oboro's ashes there, the physical place evoked in nostalgic memories by him, Gintoki and Zura.
But we never get to know anything about how long a time Shoyo and the boys were there, if it was far from the military training school or not, if they had to spend a long time wandering before getting there, etc. A popular conjecture, understandably, is to place it in Hagi where the historical Shoka Sonjuku academy was run by the historical Shoin Yoshida. However, as far as I know the Gintama manga contains no hint of its geographical setting, except that it's very much in the countryside.