A King From Another World
Yumeko was your typical average schoolgirl. Her life went normal like any other schoolgirl, until one day, a man appeared in her bedroom with blinding light and smoke. He was wearing armor and a cape. He explained that he teleported from another world to escape his pursuers.
The fact she lived alone in an apartment became a double-edged sword.
On the one hand, she didn't need to hide him from anyone. On the other hand, she was left alone with him.
He cast a marking just above her chest to ensure she wouldn't betray him.
She did everything he wanted, cook for him, and even massaged him. Until one day, he said he wanted her body.