Prologue
YEAR: 2015
Eight months have passed since Frisk freed all the Monsters in the Underground at Mt. Ebott. With his unique ability to "reset", he restarted his adventure 109 times in order to save Asriel and let him too have a happy ending. Although the young prince's soul is is in pieces, it's still being held up together in which Flowly won't comeback; that's why Alphys tries to patch up his soul once every month... but is slow and long process.
An hour after everyone got out of the Underground, they were on every news network across globe. For the first few days, the humans thought world is ending because of the Monsters appearance and tried to get rid of them. Frisk intervened every time though, even when the humans tried to "rescue" him from them.
Another few days later, the United Nations intervened. Because of Frisk's good connection and relations with the Monsters, they made the young eight-year-old the ambassador between them and the humans. They didn't want to give him the position at first due to him being young and all, but he is the only one that spend the most time the people of the Underground. Frisk left out the resets, Flowy/Asriel, and other stuff that would make humans more aggressive towards the Monsters. Asgore promised himself that he will tell the United Nations about how they got out of Mt. Ebott and the missing eight children... including Asriel.
Afterwards the U.N. allowed the Monsters to live on the surface for now on since they were imprisoned in the Underground. And they admitted that they forgot about them nearly past a thousand years ago since they always believed monsters are fictional and the fact they never heard of either the Underground or Mount Ebott. A month later, historians found a document that told that humans imprisoned Monsters in a unnamed mountain somewhere in Europe that "doesn't stay in one place after a few hundred years". They believe that the mountain moves magically from one country to the next which explains why a mountain appeared in the state of Washington ten years ago. And they reason why no one noticed that is because the mountain somehow altered the memories of humans... until now.
And since the barrier is broken, Mt. Ebott permanently stays where it's at now.
At the same time the document was found, the U.N. helped build a city for the Monsters to live in called Overhead. It has a coastal area similar to Venice of Los Angeles, the highways and city structure similar Los Angeles (located between the costal area and the urban neighborhoods), and urban neighborhoods similar to that of New York (located between the city and the suburbs), and the cliché looking suburbs with schools, parks, and a library. The suburbs is located close to a national, called Ebott Park, park that leads up to Mt. Ebott. The city was finished in five months, which is the quickest time to completely build a city, that the Monsters enjoyed living in.
The U.N. asked Frisk where his parents, and to the young boy's surprise... he doesn't know! All he remembered is climbing up the Mt. Ebott and falling down to the Underground! Heck! He only other think he remembers is his age and birth date!
The United Nations tried to locate his parents for him, but there isn't even a written documentation about either of them! It's like the young boy appeared out of thin air. This left Frisk all confused since he's now wondering why he's so determined to get back home... to what home anyway?! That didn't matter since the Dreemurrs already decided to adopt the young boy into their family... which the U.N. allowed.
After the town was finished, Asgore relinquishes royalty on Dremmurr Family (so they can live normal lives) and the monarchy over the Monsters, and thus Olive Noelle became the first mayor of Overhead.
The United Nations plans on letting the Monsters to live outside of Overhead while allowing humans to live in Overhead as well sometime in the near future.
No matter what future lay ahead, Frisk is happy with his family.
His adventure in the Underground maybe over, but his story is yet to be finished.