Princess - Princess: A Manga about Crossdressing
Been a while since I've been on S_D, but I hope you guys'll like the scans I'm posting today. Princess-Princess!
All of the characters in the above image are dudes.
So Tohru ends up being chosen as the third "Princess", and quickly adjusts after he finds out about the benefits (mostly monetary). Mikoto, meanwhile, can't quite get used to this whole "Princess" thing. A bit later in the first volume, the others teach him a thing or two.
And here, from much much later in the manga, some shots of the Princesses cross-dressing.