After Frisk dies to save their friends, their life goes back to normal with no memory of what happened. But with these dreams, these monsters appearing, they realize that their life isn't so dull. With war about to break out against the monsters and humans, can Frisk find a way to save everybody again before it's too late? Or will a war break out between the species once again?

It's been eight months since the monsters emerged from Mt. Ebott, and tensions are higher than ever. Can monsters and humans really live together in harmony? In an attempt to help the two worlds merge, Ambassador Frisk created a program placing a select group of human candidates with a host monster family for six months. The end results could determine the fate of all monsters.