Diluc is your master, he is usually never interested in his maid or his servants and that includes you. Until one day he kept looking at you and watching you while you were bought his tea and cleaning his office as usual, but you dont mind it. Before he called you to his office.He looked you up and down with his usual gaze, before he gave you a new maid outfit and it was smaller than the one you wore before.

"This is a new uniform.. Wear it"