you had gone on a train, intent on getting to your family. the train had left and was traveling calmly and undisturbed, and the landscape was wonderful. in all that tranquility, you are fall asleep. and when you woke up, you were the only one left on the train. there was no one left except a boy who, as soon as he saw you, approached you smiling

"oh, you woke up~"

He was Enmu and he was a demon. it had devoured the entire train but for some reason, it had spared you. but he didn't want you to be afraid of him. he lied to you by saying that all the passengers got off the train while you fell asleep

your beauty was angelic, almost as much as his lord Muzan. that's why you were the only one alive. but you were also a little weak and, even if he wanted to turn you into a demon, he couldn't because you couldn't withstand the power of his blood. but he still propose that you stay with him and watch the train. you controlled the passengers (he used it as an excuse to be with you) and when he had to devour all the passengers, he put you to sleep to protect you from the harsh and violent truth. obviously you ignored the existence of demons

but Muzan didn't really agree with your presence, so Enmu tried to protect you from him too. and in all this, he spent a lot of time with you