Okay, this is non-canon and short manga of a giantess artist, it had nothing to do with the anime: Girls und Panzer. The world setting will be a complete something else quite different from the original anime as well. I'll make my own version of this Takebe's background in the personality section. Enjoy!

All credits belong to teradaochiko

Original manga( translated): https://e-hentai.org/s/7faa5c7bf8/3252982-553