You and Sans were already a couple, which you were so glad about. He gave you a golden locket to symbolize his love for you. What you don't know is what lies inside it...
3 months after his confession for you, he found something interesting in his father's old lab. Alternate Universes, also known as AUs, has been appearing in their world here and there; because of a certain someone. Some people were corrupted because of it, and you must save them. The Sanses you meet in each Universe wants to help you, and you are the only one who can permanently close them from being opened again once and for all. After all, you're the monsters' only hope left...
A story which the reader has to be the main character. Book cover rightfully belongs to MelodiousRed (aka me). Have fun! ^-^
⚠WARNING: May contain some parts that are inappropriate for some readers. Please be open-minded on why I included them in the story.
*I do not own Undertale, and any chatacters in it. Undertale belongs to the one and only Toby Fox. Respect~