Why is Gintama's episode 305 full of contradictions?

Question

So episode 305 came out recently, therefore spoiler alert.

Most of it is concerning the past...

In the past episodes' flashback it was shown clearly that ..

• in this video,Takasugi lost his eye in a fight with alien.
• Shuoyou, teacher, is taken from his school and then his is returned to gintoki who cries helplessly.
• Shuoyou finds gintoki on battlefield and bring him to class with katsura and takasugi in it.

However in episode 304-305, this all contradicts

• Takasugi loses eye by attack of Oboro
• Katsura, Gintoki, and Takasugi are brought as prisoners and Gintoki is given choice to kill either students or teacher, on a top of mountain. Contradictory, to what been shown before many times: which is soldier hold gintoki down as teacher is taken prisioner and then on the same place his head returned and gintoki cries.
• In this version, gintoki is already part of the Shuoyou school and it's infact katsura and takasugi who join later on.

Answer 1

Much like @Akaik mentioned in his answer, the main reason for the inconsistencies is entirely down to both Sunrise and Gori-Sensei not entirely knowing the details of these events as they go head first into making everything.

They pretty much admit to this using Gintoki to explain at the end of episode 306, where they include another Ginpachi-Sensei segment. They even use the point you mention that previously it looked as if Gin joined Shuoyou's school after Katsura and Takasugi, when in the latest episodes it appears to be the reverse. They make a joke about it not having a script at the time and that something entirely different is happening.

This is probably as close to an offcial answer that we'll get.

There may be other mentions to why the other points you make out have changed in-between episodes but no mention of this (even as a joke) has appeared in the manga as far as I remember.

Answer 2

I'm pretty sure this is because the anime studio Sunrise didn't know much about their past either (the anime studio and the author most of the time don't have much interaction). The scene you mentioned was not shown in the manga but only in the anime.

So you can say Sunrise made a mistake just like how they skipped an important scene from the earlier episode that can prove that Sorachi was planning this right from the start.

Answer 3

Like mentioned by @Gorp, this inconsistency is mentioned in the Ginpachi-Sensei section of episode 306 and answered by Gintoki. Here's the chronology of what happened, starting from the foundation of the school.

1. Shouyou found Gintoki in a battlefield.
2. Shouyou created a school with Gintoki.
3. Katsura and Takasugi joined the school.
4. Shouyou and Gintoki entered the class with Shouyou giving Gintoki a book to wipe his ass like shown in the Ginpachi-sensei section of episode 306.
5. Shouyou's school was labeled as teaching children to overthrow the Bakufu.
6. As shown in episode 306 flashback, Shouyou stopped some patrol from drawing their swords against Sakata Gintoki, Takasugi Shinsuke and Katsura Koutaro.
7. Shouyou got arrested but was later released, probably with strict warning that this is his last chance and he must stop teaching. This is where Gintoki is shown crying upon his return.
8. Shouyou ignored the warning and continued to teach as shown in the flashback where Gintoki said that the Bushidou Shouyou taught and they follows won't be bend by such a thing (the threat).
9. Shouyou teach again for some years and was then arrested again. This fits with he fact that when Gintoki and friends fought in the war, they are older than when they are in school.
10. Gintoki and other Shouyou students formed a rebel group to save Shouyou.
11. The Dragon of Katsurahama, Sakamoto Tatsuma joined the group and act as the fund raiser.
12. As shown in the flashback where Sakamoto and Gintoki crash landed in a desert planet (it was in the first or second season of the anime, I forget which episode), Sakamoto said that he thinks that fighting is not the only way to protect things he deemed precious. He left the group and formed a trade company.
13. Sakata Gintoki, Katsura Koutaro and Takasugi Shinsuke got arrested and brought to a hill where Yoshida Shouyou is.
14. Gintoki chose to kill Yoshida Shouyou, his teacher, to save Takasugi and Katsura. His head was indeed returned to Gintoki. The setting might differs but the essence of the story is the same.

As for Takasugi losing his eyes to Oboro, it indeed differs from what shown before. Most likely it is because of both Sunrise and Gorilla-sensei didn't think about it when the scene was made. Which is also confirmed by Gintoki in the Ginpachi-sensei section of episode 306.

Answer 4

Back then it's a fake trailer. Gori-sensei didn't write that. Ep.305 however, is canon.