Mysterious Note

When I woke up, although I felt tired, I felt fulfilled. Beside me, Ember was hugging me tightly with a smile on her face. I spent a few moments watching her cute face, which made me smile, before leaving a kiss on her forehead.

I covered Ember's body with a blanket before I went and wore my scattered clothes. As I was getting dressed, I noticed something that wasn't there before—a piece of paper lying in the middle of the white floor. It was yellowish paper, like a scrap from an old notebook's page.

"Who left this here?"

I picked it up and inspected it. The cut was jagged all over, as if it had been roughly torn off. I looked at it all throughout but only found one word written on it: "Sorry."

"... What?"

There's neither the name of the sender nor who this message was for.

"[Sorry]?"

"Uwah!"

I was surprised as Ember suddenly appeared over my shoulder, peeking at the note I was holding.

"Ember?! W-, tell me if you're awake!"