[Guido]

Finished Karneval today. The final episode yielded the culmination milestone for Gareki to become even more committed to further his personal growth, after all the experiences he lived through and witness by himself remaining with Circus.

I did sob when watching Gareki containing his tears feeling he couldn't accomplish anything on his own in the battlefield and flagelated himself for keeping everyone down. That drama was more personal than powerful, because in real-life we can relate to that same frustration and humiliation; the idea at first you knew how to adapt and survive in your enclosed world. Then, when exposed to something out of the bounds of your world, then you come face to face with the (maybe bitter, maybe ghastly, or maybe exciting) realization that the world is a bigger place than you thought, and what you learned so far is not enough to assure you're going to continue adapting, living, and running your life like how you used to in your world.

I do concede that Gareki is the main protagonist, indeed. Because all those out of the world experiences he got himself involved with that suddenly shattered the rhythm and foundations of his ordinary world. Moreover, the more he interacted with Nai and Circus the more he began to approach them cautiously, little by little, but steadily. And, the more Gareki came face to face for the first time against his own uselessness in that new and bigger world.

It all resonates throughout the rest of the final episode setting up a scene that to me felt very nice and cozy, as if it was a discussion amongstfamily siblings. Tsukumo, Yogi, and Nai all seated in one room discussing about Gareki's fate and admitting amongst themselves that all dread the thought about Gareki leaving them forever.

However, it is interesting to take notice that, first, we start with Gareki getting any response from Hirato, if there's anyway for him to enroll at a Government academy without a family register; Hirato's response was that he'll see through it, but that his participation up to that point ends there, meaning whether he excels and brings good results or not that would be Gareki's full responsibility and choices.
Then, later as Tsukumo, Yogi, and Nai discuss on Gareki, Yogi mentioned he would feel terrible if Gareki actually joins as a child to the Second ship recalling his own experience when first joined Circus. In order not to endager his whole family and not to be shackled by those feelings of worry and concern, he had to strip himself off of his previous identity: all his family register and civilian profiles were erased.

This means that the prerequisite to join Circus is that one must erase everything about his persona from his or her past to likely his or her previous name, becoming a non-existent shadow to the rest of the world. Hence, I see why the members of the Circus Ships that do the fighting and arrests are so few. To abandon everything and becoming a sort of deja-vü to the rest of the world is a life-altering choice and never an easy one.

Now, how does that has to do with Gareki? - It has a lots to do, since Gareki never had a family register, hence, to the world itself he's like another non-existent shadow.
I speculate that whatever setup by Hirato, then he sent Gareki to a Circus sanctoned, training Academy; my gist.