-YEAR 2169-
Mankind faces a great problem. The sun is exploding in two years. But this time, they were prepared. The big nations (America, Russia, China, Isreal, Germany, and England,) sent out one human each to find a place big enough underground to rebuild humanity. But then, one day... A child named Frisk, who had gone missing a year ago, came back and told everyone of this huge place underground. It was under Mount Ebott and had some things already down there- it even snowed, which was weird. And so, Ebott City and the rich assholes of the world headed down. And the first thing they met was an anthropomorphic goat lady in a royal gown and a nine-foot-six skeleton in a lab coat.
-TWO MONTHS AFTER-
Humans are building real houses down here- ones more advanced than the ones monsters already built. The species rarely ever mingled with monsters. But the two species still interact. The monsters had always wanted to see the stars, but when the humans told them about the sun exploding in two years, they decided against going up now. Their king, King Asgore Dreemurr, had absorbed the seven human SOULs he needed but still had yet to break the barrier.
-2169, AUGUST 2ND-
You were wondering through your home sector, the Hotlands. Today, you had decided to explore the Hotlands a little bit to get to know your new home better.
You were one of the only... What? 15 humans? that actually liked monsters, including Frisk. So you decided to take a break at Sans' hotdog stand (he's probably one of the few monsters that actually enjoys your prescence like a friend would,) to have some hotdogs (and fund Sans.)
As you were eating your hotdog, though, Sans called you over. So, of course, you went over.
Sans: this is w. d. gaster. i thought you two might be good friends if you tried. anyways, i'm taking a break. you two know where to find me.
And off he teleported, leaving you alone with the skeleton scientist that had met the first humans with Lady Toriel.
You ate a hotdog.