This is an ordinary Star Vs The Forces Of Evil Story, except, you can make choices of your own. I will explain how this will work inside, but for now, on with the description...
Monsters are invading earth, everyone Marco has known and loved is gone, taken by the monsters. Everyone apart from Jackie Lynn Thomas. The pair escape and luckily come across an old abandoned house, where they find a young girl, after a huge episode, they manage to persuade her to let them stay for a while.
Star and Marco have just graduated from Earth high school, and they couldn't be happier! Well, Star could. Marco and Jackie are getting pretty serious, and he's made a habit of neglecting his other friends, including a certain princess with a secret love for him.
But everything changes when Star is called back to Mewni to seal a long-awaited for peace treaty with the monsters...by entering an arranged marriage with the son of Toffee!
Star has two weeks to decide whether to go through with the marriage or wage war with the monster army. Which will she choose? Will she stay on Earth with Marco? Or walk down the aisle instead?