Use a tool like WinRAR or 7-Zip to extract the files into a new folder.
Many characters, models, and animations were temporary, giving the game a unique, raw feel.
The rapid iteration during 2015 is astonishing to look back on. The Update History page on the Yandere Simulator Fandom wiki shows a breakneck pace of development. Here is a summary of the foundational mechanics that were laid down in 2015: