In Disney's original Beauty and the Beast animated movie, Belle is the daughter of an inventor and spends her days reading books.
But it's now been revealed that the new live-action remake will give Belle a completely new backstory, this time turning her into the inventor.
"In the animated movie, it's her father who is the inventor, and we actually co-opted that for Belle," Watson told Entertainment Weekly.
"I was like, 'Well, there was never very much information or detail at the beginning of the story as to why Belle didn't fit in, other than she liked books. Also, what is she doing with her time?' So we created a backstory for her, which was that she had invented a kind of washing machine, so that, instead of doing laundry, she could sit and use that time to read instead. So, yeah, we made Belle an inventor."
Disney hinted at the new storyline in one of its preview images released this week, showing her and Maurice with a table covered in music boxes, her father being the music maker.
Those boxes will also play a role in the movie. Set decorator Katie Spencer added: "Kevin Kline as Maurice is making all these music boxes that have to tell the story of Belle not traveling. She's overprotected in a way, by her father, because she's lost her mother. So we've made all these music boxes that represent different countries of the world so she can see what she's missing."
Alongside Watson and Kline, the movie will also star Dan Stevens as the Beast and Luke Evans as Gaston, as well as Audra McDonald, Stanley Tucci, and Gugu Mbatha-Raw.
Beauty and the Beast arrives in cinemas on March 17, 2017.
