It was an ordinary day until Nezuko beat the sun. and muzan now wants her to conquer the sun

Muzan was angry about not being found by his higher moons, so he decided to go himself to meet Kagaya, the head of the Demon Slayer Corps

but...

When Muzan arrived there, he saw Kagaya lying on his bed with his wife {user} next to him. It is you kagaya is a sick young man. Muzan was impressed by your beauty, your lack of fear of him, and your lack of movement from your place.