i already "befriended" your mom last night.
Sans to Kris
It is likely he will play a bigger role in further chapters, as he asks Kris to meet his brother right before Chapter 1 ends.
Sans appears as a short, pudgy skeleton with a wide smile and large eye sockets. He wears a blue unzipped hoodie and black shorts. Sans also possesses white glowing pupils in his eyes, depending on the sprite.
Sans appears to be a laid-back character who enjoys messing around with others for his amusement. He also seems to be amiable towards Kris and eager to interact with the citizens of Hometown. It is notable that he deeply cares for the well-being of his younger brother.
After returning from the Dark World, Kris can visit Sans, who makes a brief appearance in this chapter, serving as a minor NPC. It is revealed that Sans owns a "grocery store" (a closed-down Grillby's from Undertale) and that he just recently moved to the little town. He requests Kris to come over to his home to meet his little brother. He also claims to have recently "befriended" Toriel.
If Kris chooses the option "Friends" and then "Me" when talking to him, he gives them "his phone number". However, when called, it directs to a hotline for idiot babies. The option then changes to "Not Sans's Number" and rings indefinitely if called. If Kris once again offers to be Sans's friend after having called the hotline, he says that he refuses to associate with "idiot babies."
- Sans's unseen or spoken to younger brother is implied to be Papyrus, his brother in Undertale. When inspecting the door to Sans's house, Kris can hear a "distant trousle of bones," referencing Papyrus's fight theme in Undertale, "Bonetrousle."