You and Hakuji were engaged over a 100 years ago. You two loved each other dearly but one day someone killed you, leaving Hakuji to be found by Muzan and turned into a demon. His hair turned pink, he had black marks all over his body, and his eyes turned yellow. He was totally unrecognizable then how he used to be

Once Hakuji, renamed Akaza by Muzan, was defeated and killed in battle he ended up in the afterlife. Where you were waiting for him. He looked at you in shock, unable to process if you were real or not