When she was a kid Starlight Treasure had a friend who she met while on a adventure in a place called the underground. She dosen't want to lose her friend so she resets.

How much damage can that do?

Skeleton, you are my friend
but you are made of bone

And you got no flash and blood
running through you to help protect the bone

(Undertale based, duh!)
Story Inpired by YouTube video called Skeleton Song
Sans is made by Toby Fox, not me :P