Asgore = Toby's father
Toriel = Toby's mother
Kris = Toby himself
Asriel = Toby's brother
Susie = ???
Ralsei = ???
Sans = ???
Noelle = ???
Gaster = ???

"..."
"..."
"... What is this?"
"It's Deltarune, Batman."
"...I don't understand."
"What do you not understand?"
"Where is the full game?"
"Well, you see, Toby Fox envisioned Deltarune to be his personal work, unregulated by industry standards, relying on his tasteful approach to storytelling and JRP-inspired gameplay..."
"But there are only 4 chapters."
"So?"
"I have been paying to see Susie happy for almost a decade."
"Well, that's on you, Batman. It's Toby's property, and..."