From Shoujo Crusade:

[It's okay to be a servant, I want to be by your side...!]
[You'll treat me really really well?]

Mayuri, a girl who wanted to be acknowledged as herself shares the same room with her senpai, Akira who is the student council president and a beautiful person envied by others. But, Akira has a big secret...?
Somehow, her real self is a "boy"!?
Moreover, he makes a petition of wanting to be Mayuri's servant...?

Thus, the wonderful room sharing life of the domineering (!) beautiful girl, Mayuri and a boy wearing girl's clothes who's also a bit of a trickster (?) Akira starts.