- The monsters have only been in the Underground for about 60 years when Frisk fell.
- Frisk and Chara are both female.
- All the humans that fell down are still alive.
- Frisk and Chara are the only fallen humans adopted by Toriel and Asgore.
- Both Frisk and Chara go to "Tri-City School."
- Alphys is not the royal scientist.
- Mettaton is a ghost named Mayton.
Other Important Characters
- Bratty and Catty
- Monster Kid
- The human with a yellow soul [TO BE NAMED]
- The human with an orange soul [TO BE NAMED]
It is the same story as "Undertale" until the point where Chara tells Asriel her plan. Asriel tells Chara that he doesn't want to kill anyone, and that Chara could absorb his soul instead. Chara refuses to allow Asriel to sacrifice himself. After this, they just grew up together, and Chara decided to go to 'Tri-City School' instead of being homeschooled with Asriel.
Six more humans fell, and all either got adopted by different monster families or went to live on their own.
Just before Frisk falls, some tension about the fact that they have enough humans to break the barrier arises. Several monsters suggest that when the next human falls they take their soul to use because many monsters do not want to sacrifice Princess Chara. When Frisk falls a short time later, Toriel and Asgore adopt her to keep her safe as well.