My Sham Marriage to the Onigami

In Edo-era Japan, demon hunter Eve is hired to assassinate Onigami Mei, the feared Demon King. Their battle ends with half of Mei's soul sealed inside her. To survive, Eve infiltrates the Onigami Clan, posing as his fiancée who vanished five years ago. When Mei returns with no memory of the past, she forges a shared history built on lies. But as enemies become lovers and the truth closes in, Eve falls for the very man she was sent to kill.