A/N: Frisk will be identified as a sixteen year old female in this story. There will also be Frisk x Asriel, but that's not the main pairing. All Characters belong to the brilliant Toby Fox. Enjoy! :: PROLOGUE :: Frisk was a simple girl. She was quiet, didn't ask for much, and always held a look of unshakable determination in her eyes. Ever since she'd fallen to the UNDERGROUND four years ago, things around her had changed. She was no longer surrounded by people who neglected her existence like the humans; instead, she showed mercy to the monsters of the underground, who in return welcomed her with open arms. The once young human girl, Frisk, had, over the years, become a beautiful teenaged girl who taught the monsters the many things she could remember about the human world. Asgore had given up trying to reach the human world, seeing as how everything had seemed to settle peacefully. But when she's faced to deal with the coronation of Prince Asriel, how will she deal with it when she doesn't know how to sort out her feelings?

I decided to combine two aus I kind of know. They are uppertale and voidtale. Sans who has fallen in love with Frisk hasn't told them yet. Now it's to late because Error has kidnapped Frisk. Now he has to save them before something bad happens and error kills them. Will Sans make it or will this story end tragically.

The barrier has been broken for a few years now. Monsters and humans have been living in peace together . . . for the most part. There are rumors about a monster who can somehow change his appearance into a big, scary dragon like skeleton thing. His name is Sans, and as you find out, he's not really that scary, just scared. This is my first ever X Reader, so keep that in mind. Please be kind and if you have any suggestions, let me know! Also, I guess it's kind of a slow burn . . . Art belongs to me. I don't own Gaster Blaster Sans. If you like this story I'm also working on the back story to how Gaster Blaster Sans came to be. It takes place long before this story when W. D. Gaster was still the royal scientist. You can now ask Gaster Blaster Sans: https://www.wattpad.com/story/76026518-ask-gaster-blaster-sans/parts

Intro: The barrier was down. It had already been four week. Most of the humans were not pleased with the monster arrival, but since Mont Ebbot was a bit far from the city and that no one ever goes their (for most part of the population at least) they allow the monsters to rebuild their society on it and around it as long that they keep their self far away from the city. With their magic it only took a few days for everyone to be set .It was a new start for monster kind, now they would only need to make their relation with the humans better. Everything was for the best; well it was until the little human that had free the monster got her secret exposed. --- -A/N- -Undertale and all of it's characters belong to Toby Fox -My first language is not english -Frisk is a girl in this story -I don't know when I will be abel to update but I will do my best to not be to slow -Don't esitate to give me some feedback it's my first fanfic :) ---