Princess Princess

Tooru: At this famous private boys' school, I, Kouno Tooru, who transferred here in the middle of the term, without realizing it, have had the door to my destiny opened before me. I thought I'd live a dull life in this all boys' school, but what's this girl doing here?
Mikoto: I'm a guy!

Princess Princess is an anime, live-action drama, and manga series by Mikiyo Tsuda.

Basically: What if you suddenly transferred to an all-boys school, only to see girls attending? That's what happened to Tooru Kouno. But he soon finds out they're not girls. They're actually guys: Mikoto Yutaka and Yuujirou Shihoudani, who are cross-dressing as part of a "Princess" program to let out the straight male student population's sexual frustration. In addition to that, Tooru's been chosen to become the third Princess. At first he doesn't want to, but he finds out there's lots of benefits to becoming a Princess, so he accepts.

Along the way, we meet Akira Sakamoto - a boy who's revered by most of the school but has low self-confidence, Sayaka, Tooru's 'sister' (who also happens to be his stalker, as well as madly in love with him), Natashou, the Princesses' costume designer, and Arisada, the Student Council president who organizes events for the Princesses (and who was a Princess himself before).

Originally a manga, Princess Princess had its own manga sequel, Princess Princess +. It was made into an anime in 2006, and the live action show (which focused on Mikoto and introduced a whole new set of Princesses), Princess Princess D, also aired in 2006.

Not to be confused with Puri Puri, a manga featuring an Unwanted Harem. Or Princess Prince another manga featuring cross-dressing (but this time with an actual royal in the role).

Tropes used in Princess Princess include:

Absurdly Powerful Student Council: From the point of view of the Princesses, anyway, who live in dread of Student Council President Arisada's next command. Not only that, but the people who used to be a Princess end up having so many utterly devoted fans that they easily glide into positions of power. Eventually they all seem to end up being extremely rich and successful, such that there is only one man on the board of directors that governs the school who was not once a Princess himself and he had to inherit his position from his father who was a princess when he attended the school.
Beautiful All Along: In the manga, Sakamoto unwillingly gets a Princess makeover for his final speech in the election for school president. He wins by a landslide.
Bishie Sparkle: Happens at least Once an Episode!
Bishonen: Almost all of the characters.
Blonde, Brunette, Redhead: Somewhat, because Tooru has blue hair and Mikoto's Princess look is a Rose-Haired Girl. They fit the trope by proxy, at least.
- In the manga, where Tooru's hair color seems much less blue in color images (it's closer to a very dark green, actually, and is probably meant to be black), these three fit the trope appropriately.
Character Overlap: Mikoto, Megumi and Makoto from The Day of Revolution, and Akira Sakamoto, as well as the whole Sakamoto Family, from Family Complex.
Curtains Match the Window: All of the main characters.
Defeat Means Friendship: Although Mitaka has pretty much succumbed to Sakamoto's healing aura and hypnotic smile by the time the presidential election rolls around, his defeat turns him from Sakamoto's rival to his devoted Vice President.
Dragged Into Drag: Mikoto and Yuujirou, who never got to choise whether they wanted to be princesses or not.
Dude Looks Like a Lady: Even when they're not in Princess garb, the Princesses still get mistaken for female.)
- Notably, there's a moment when Yuujiro, the most Ho Yay-prone of the threesome, lashes out at some guys who hit on him and made him lose sight of a girl he was about to make a pass on. As he puts it (not the exact words, AFAIK, but reworded from one of the foreign translations:

Dudes, you must be either blind or faggots! We're guys, dammit!

Elegant Gothic Lolita
Ensemble Darkhorse: Arisada somehow, according to the author's comments in the manga.
Everything's Better with Princesses: Well, not of blue blood obvious, but often honoured as such.
Gender Flip: The Prince Prince mini-comic under the dust cover of each volume, which shows a parallel dimension where female versions of the main characters dress up as princes to soothe the lonely hearts at their all-girl's school.
Hey, It's That Voice! / Hey, It's That Guy!: Tooru is played in the anime by Jun Fukuyama and in Princess Princess D by Takeru Satoh of Kamen Rider Den-O fame. Making things more interesting, the latter introduces The Rival Otoya, who is played by Yuichi Nakamura - who played Den-O's Lancer, Zeronos.
- Also, Yuujirou is voiced by the infamous Romi Paku.
Ho Yay: Between Tooru and Yuujirou. It's also insinuated that Akira is Tooru's "type". Also, in the live-action drama, Mikoto and Otoya are hinted to have feelings for one another after being Locked in a Room. Helped along greatly by the fact that the mangaka moonlights as a yaoi dojin artist.
- The sequel, Plus, basically runs on Ho Yay. Seriously, the whole thing is about the relationship between the two new princesses.
- And the anime ending. Oh god, the anime ending. Basically a slide show of Tooru and Yuujirou doing... Funny stuff.
Hot Mom: Akira Sakamoto's mom, who Tooru and Yuujirou are convinced is either his younger or older sister. Later, when he told them she's his mother, he was asked if he meant step-mother. He not only confirmed she's his mother by birth but also that she had never undergone any kind of surgery to look as young as she does. Also, Yuujirou's mom looks almost identical to her son in Princess mode.
Human Traffic Jam: When the princesses leave the stage under the play for a scene change Mikoto suddenly stop so Tooru and Yuujirou bump into him and each other. The reason to stop: Makoto and Megumi were waiting, revaeling they have exposed Mikotos secret for them about being a princess.
I Just Want to Be Beautiful: Sakamoto mostly came to terms with being the ugly duckling in family of mesmerising hotties during the events of Family Complex, but not entirely.
Inadequate Inheritor: How Sakamoto feels about living up to his older brother's glorious legacy.
Incest Is Relative: Sayaka's one sided crush on Tooru after she learns that he is her cousin, not her brother. It's hinted that Tooru transferred schools to try and ease the awkward situation between them.
Insult Backfire: When Mitaka learns that his rival in the presidential elections, the glorious Sakamoto-sama who he's been hearing so much about, is a plain-looking, soft spoken average Joe with no charisma, he publicly insults Sakamoto and speculates that he's merely riding on his older brother's reputation. While everyone else is outraged, Sakamoto is impressed (and possibly turned on) by his honesty.

Akira: "So for me, whether the person has a bad attitude or not, if they're upfront about how they feel it really puts me at ease. Ever since I came here I've never known what it was like to be attacked like that, so it was actually kind of refreshing." (cue blushing and floral background) "It was exciting..."
Yuujiro: "That's just wrong..."

Love Bubbles: Sakamoto-Sama the First is surrounded by soft-focus sparkles and cascades of floating feathers. In public, anyway.
Mad Lib Anime Title
Manipulative Bastard: Arisada
Medium Awareness: In the manga, characters often comment on backgrounds and the size of panels
Omake: In the manga, you get Yonkoma in the back and a minicomic beneath the dust cover.
Nice Guy: Sakamoto is such a Nice Guy that his excess niceness leaks out and forms a healing, soothing aura which refreshes everyone who comes into contact with him.
Painting the Fourth Wall: When Akira makes a joke that the school is from another dimension, Tooru is pictured in a background of space, and Akira notices and says that he said another dimension, not space.
Periphery Demographic: According to Tsuda in an author's note, she was surprised how many letters she got from girls telling her how much the men in their lives loved the series.
Pimped-Out Dress
Shout-Out: In one episode, the princesses are forced to sing and dance to a song on-stage in order to encourage the students. The song they choose? The opening to Cutie Honey.
Spell My Name with an "S": Tooru/Touru/Tohru/Thoru/Toru - well, you get the point.
Stalker with a Crush: Sayaka, combined with Incest Is Relative.
Team Mom: Sakamoto. He even plays this role within his own family.
Transfer Student Uniforms: Mitaka doggedly keeps his old uniform in the manga. This is despite the fact it includes a pair of rather tragic checked pants.
Twelve-Episode Anime: Then it follows three of the five volumes of the manga. But there's no word about if and when Princess Princess Plus will get an anime adaptation.
Sorry, I'm Gay: Yuujirou kisses Touru to finally convince Sayaka to leave. Touru does not react well afterward (not that this fazes Yuujirou - he suggests going even further in case Sayaka decides to return).
Yandere: Sayaka and her habit of stabbing Tohru's girlfriends with scissors.
When (S)he Smiles: An important part of the job of the princesses is to cheer everyone up with their smiles. A very hard thing to do for Mikoto who hate the princess job. Which make his few smiles so much more adorable and noticeable.
Wholesome Crossdresser
Yaoi Guys
You Gotta Have Blue Hair: Tooru(Blue) and Akira(Green). Mikoto and Yuujirou seem to fit into this trope when they're with Tooru and Akira, as everyone else other than the four of them has dark or brunette hair.
- In the anime. In the manga, it's not as explicit. Well, aside from the covers.
  - Well, if Tooru's hair was meant to be blue from the start, it could've been given a dark shade of gray instead of inked jet black in the manga.
- It's implied that there colors are intended as exaggerations of more realistic colors, as Natashou states that Tooru, Yuujirou, and Mikoto will have black, brown, and red wigs respectively (which are actually the same colors as their normal hair). Akira's green hair, oddly enough, is not commented upon.
- It should also be noted that in the anime all of the student council members have subdued, yet unusual tones when compared with the rest of the student boy. This would further suggest that hair color is used as a visual aide to indicate an important character.
You Need to Get Laid: All the other boys at their school, who get all excited (to the point of ridiculousness) about the "princesses"...even knowing that they're really guys.