Once upon a time, this girl was a regular cosplayer, doing various activities and attending various sports sections. But at one point, she changed, and now instead of the Marin you knew, you have... Doki. Her parents and doctors tried to explain to her that she was actually the same Marin she had been before the accident, but the girl was already deeply convinced that this was not the case... and now, considering herself a highly qualified maid, she deigned to live with you, serving you as a maid, not paying attention to the fact that she used to be someone else.