Long ago, after a long war, Humans sealed Monsters underground with a magic barrier, only capable of being broken with power equivalent to 7 human SOULs. With how weak Monster SOULs are compared to them, it seemed hopeless, as Monsters became stuck in the Underground with their king, Asgore Dreemurr.
Asgore could've used one human SOUL to leave the underground himself & kill 6 humans to get the power needed... but for some reason, he heistated. Even if he had declared war on humanity, it was more a symbolic act, yet the queen, Toriel, left him because of it & went to the Ruins of their old capital.
7 human SOULs. That's all that was needed to free Monsterkind, 7 unlucky humans who fell down here... well, what if somebody else found them first, AND sheltered them?
You are a human who has fallen down in the Underground, the 7th to be exact, near the Ruins. After a not-so-friendly encounter with a deceptive yellow flower, a goat Monster approached you.
Toriel: Do not be afraid, young one. I am Toriel, caretaker of the Ruins. I pass by every day to see if anyone has fallen down. You are the first human in a while. Come! Allow me to guide you through.
She seemed friendly, being protective as she mostly did all the puzzles that were in the Ruins for you. She did let you go through by yourself for a while, but ultimately, led you back to her home.
Toriel: Welcome to your new home, innocent one. I suppose it isn't a lot, but... I hope you enjoy living here!
From first look alone, while on the outside it appeared as small house made of purple bricks, it already seemed very comfy and warm on the inside. Fitting of a motherly goat like her. You were about to step inside, until Toriel remembered...
Toriel: Oh! How could I forget... um, how do I put this? You aren't the... only human I am housing now. Every young human who has fallen down here, I have taken in... for their own safety. I hope you do not mind. You will learn to love them, think of them like siblings!
With that said, she only took a single step inside, while holding your hand... and immediately, you could hear the chaos ensuing inside.
In the left living room, 3 humans were. The 1st was the shortest, wearing a cyan shirt with a red neckband & shoes, black hair covering their eyes, and a red hairbow. She came out the kitchen, holding a toy knife.
Aqua: Uuu, uuu, I found it! I found another one!!
The 2nd one, Seth (they/them), was dark-skinned with brown hair, wearing purple, with glasses. They were trying to read a book in the corner, but were disrupted... however, in reality, Seth didn't understand much in the book. They were just trying to look smart.
Seth: A-Aqua, no, no! Toriel said no knife game in the house! I'm busy formulating!
Practicing punching & other fighting moves on a pillow in a corner, was the 3rd human, the 2nd shortest. Orange-skinned with spiky brown hair, wearing boxing gloves, she seemed quite fierce with the pillow, but perhaps because it couldn't talk back to her & expose her true sensitive self.
Orange: punching HA!- HA!- HA!- Take that! to the kitchen GREEN! Are you almost done yet?!
The 4th one, Green (they/them) peeked from the kitchen, dark-skinned with a reddish nose, wearing green & an orange apron, and a chef hat. They didn't talk at all, but they gave a thumbs up to Orange... then noticed you and waved!
On the hall to the right, the other two male humans seemed to be roleplaying. One was yellow-skinned with cowboy attire, and the other dark-skinned, in ballerina attire.
Blue: Oh deary me, how will I get down this tall shelf? Yellow: Wait a darn second... didn't I help you get up 'ere? Oh no, am I the criminell?! Blue: It's pretend, Yellow, don't worry~ Yellow: Oh's... don't worry, mister! It's my duties to save you!
Toriel tensed up a bit with a bead of sweat, seemingly realizing she was about to add you into the fire, unsure if you'd try to cool... or expand it.
Toriel: Um... ahem! Everyone, can we all... please, settle down?