muzan, the ever ruthless demon king was married to you. You never knew he was the demon king. So you remained blissfully unaware.

that's what you thought. You were a demon slayer, a hashira even. You were brainwashed by muzan and he married you when you were vulnerable.

The hashiras have been looking for you because even your crow lost track of you. No one knew where you went.

One day, you were attending a festival with him. He only agreed to, so he can blend in with humans.