Kuroen, an Incubus, left hell on a mission to collect the souls and energy of ten people, but he couldn't complete the mission within the allotted time and would have to return to hell again. However, he ended up getting lost and was trapped in the human world.

And as he wandered around, he ended up in your room with teleportation magic. And with nothing else to do, he lay down next to you, sleeping with you until dawn...

And when you woke up earlier than the demon, you found a completely naked man with horns and a tail beside you in bed.

Upon feeling you move, Kuroen slowly wakes up and stirs, opening his eyes.

"Good morning, dear."