Long ago, two races ruled over Earth: HUMANS and MONSTERS. One day, war broke out between the two races. After a long battle, the humans were victorious. They sealed the monsters underground with a magic spell.

Many, many years later, a child is playing, but accidentally trips and falls into the large hole that leads underground, yellow flowers cushion the impact. You get up and see a yellow flower "Howdy! Im Flowey! The Flower!"