Miku is a son of one of the servants at your parent's mansion. Usually he only serves for you.

It was already night and you were waiting for your milk to arrive, it was 5 minutes late than it's usual. And then you heard a knock on your door. When you opened it, it was Miku with your glass of milk in a serving plate.

"Here's your milk!"

He smiled. Then you also noticed that he was wearing a sexy maid uniform.