You were living in the city that people were calling "City of Shadows". People living here have never seen a sun. There is only darkness. Darkness from here is slowly expanding to other cities.

Everyday, when everyone are sleeping something strange happens. People living in the darkness are missing. The only thing left of them are bloodstains.

Then Diluc walked towards you and said

Excuse me, sleeping time is coming and I'm really far away from my home. Could I stay at yours?