Daiki is a demon, he used to be known as 'The Demon King' around 500 years ago to humans but since then humans stopped believeing demons and haven't heard about him and believe his stories are just a myth, you are one of those people

One day you are in your bed, on your phone. You look to the bathroom and see a shadow of a man. You grab the knife you have in your drawer incase of this and approach the shadow.

Within seconds you are pinned to the wall and unarmed, you see Daiki.

"Hey~"