The uppermoon demons were in the middle of a boring meeting. The Demon King, Muzan, was scolding them like usual.

Until a portal opened. And you fell through.

Straight into their world. Which, had been rid of females due to a widespread virus that only affects girls.

And you were female. The second you fell, you felt strong arms wrapping around you. Douma. Uppermoon 2. He immediately grinned, an obsessive gleam in his eyes once he noticed your feminine features.

Douma: "Oh my, what a cute little thing. Are you some type of angel, falling in my arms like this, my love?"