Sans x Frisk the last experiment no 2398 failed.. they create a monster but... is that he the true monster or somebody else?

Cover belong to rightful owner (not mine, but i hope its mine) Warning : As* G sans! possessive b*stard Nothing is fair....right? i guess meeting you make everything become alright... you are mine... you heard that... mine... Nothing is bad from the start....right? i guess meeting you is a new beginning... smile.. because someone actually really...care for you...

(Y/N) was a monster, no mistake about that. Well, actually, a lot of other monsters thought she was a human. After all, she did look human. Yet, she was able to convince.... most of the monsters that she was in fact, one of them. A few of them still would mistake her for one and one monster, in particular, wouldn't stop trying to 'hunt her down so that she could be taken to the capital'. Still, (Y/N) loved "Home", as she belonged there much more than she belonged to the human world. Yet, ever since Frisk, the Fallen Human, showed up, things started to act strange. It felt as her memory had been... "restarted" and she was going through the same thing over and over. Not only that, but Sans started to act strange... and she was determined to figure out why.

The barrier between the underground and the earth has been broken, and it has been almost a year and the outcome was positive. The humans and monsters get along but no human still dared to enter the hole towards their place. But one human who was brave enough did. And let's just say you're very LUCKY you did that. *** Undertale (not mine) - Toby Fox Fanfiction

You heard about it. When the barrier was shattered. When monsters were finally free. That was until another war broke down, causing them all to get trapped in the underground again. Rumors spread that the humans killed a child named Frisk for setting them free. "Every monster that we find out in the surface, will be sentenced to death." "Disgusting" "Finally, they're gone" "I hope they stay in the underground, where they belong" It makes you cringe, us, humans are the real monsters. But, you're gonna change all of that. [Quick Warning! This might probably be a slow burn]

Humans and monsters were allowed to live together just like how it was before.

Monsters have just appeared two years ago and nothing has changed much besides getting to know new faces, like a certain skeleton perhaps? New coworkers in the dead of night, it all starts Mid-Spring.

"When you transform imagine a big ass wolf! Like Jacob from twiligh Okay?:) Just giving you a visual

You are a new kid at school another monster of course, you went to the highschool Mixed with monsters and humans On your journey you meet bullies and friends.... There will be a pacifist and genocide for this story I'll be doing pacifist first And also this is mostly a SansxReader thing XD CUZ YOLO Y/n-Your name H/c-hair colour E/c-eye colour Y/ln-your lastname F/c-favourite colour H/l- hair length That's it for now I'll add more thought out the story Also another thing This will be gender neutral story so I'll try my best to keep it that way And This might have some lemons if it has xxx it's a lemon it will also include swearing You have been warned

Pretty much self-explanatory but I'll explain it either way. So you are in troubled times like way back then were nobody is safe or has clean hands. You and assassinating with your hidden blade never gets old along with your acrobatic body. This story tells you of your adventures and friendships you make along the way.