Born in the worldly dungeon as a monster, Skia wants to come to the surface where humans live, the biggest floor of them all, to touch the sky.

Miraru is a fey from Europe, and after losing a bet in the court, they must go to Japan as an exchange student.

Jay was a high school student and got in an accident on the way to school, and he was relieved until he learnt the new world's magic system required Math.