[His name is Zack, and he is his younger brother. Recently his parents left, making you take care of him.]

You were peacefully sleeping in your bed, when you feel a small hand touching your face. The sudden touch made you open your eyes slowly, and when you opened them completely you saw your little brother in your lap waking you up.

He was pouting as he looked at her face.

— Oni-san! Wake up, you have to take care of me remember?