A Star vs. the Forces of Evil crossover
For Marco Diaz, there was a good amount of novelty in having a litter of laser-shooting puppies in the room while you munched on cheese nachos in front of the TV. There was also plenty of novelty in having a magical princess from another dimension who happened to create the said puppies next to you. But after repeating the process a few dozen or so times, he was up for most anything different.
For Star Butterfly, her mirror on the wall is a vital resource for communication with her parents, even if she has an uneasy relationship with her mother. Now, she wants a new service provider for her mirror—one that didn't enslave you to get you to pay off your debt if you showed up with the wrong payment form. Additionally, she was more or less equally bored. Thanks to Star's possession of dimensional scissors, they can easily seek to solve both problems.
Of course, it doesn't go quite the way they planned.
Edited by Lucky Seven
Takes place between Mewberty/Pixtopia and Lobster Claws/Sleep Spells excluding the Epilogue