Omake
Rumours abounded of a beautiful redheaded girl, seemingly the elder sister of the High School senior Rias Gremory who would sometimes appear in the Occult Research club. She was tall, and almost unapproachable by the local school populace, with an unmatched elegance that could only be made by such a mature woman. Although many had questioned why exactly a college aged student would be lounging about in a high school campus, there was little to no doubt that whoever the girl was, she was not someone to be trifled with. Her clothing was a bit queerer, apparently being a a skintight dominatrix outfit, or something similar to one, but confirmation was not available.
This, of course, came to the attention of ones called Motohama and Matsuda, a duo of voyeurs and delinquents infamously known as the perverted duo. Being the dedicated bunch of losers and nerds that they were, they wanted to know more about the mysterious waif, whether it would be her history with the club, her measurements, or even her personality. Any of their attempts to gather information went straight down the drain however, as either asking the people who knew of the members of the club didn't know enough, or the members themselves who simply refused to answer. When they tried asking a certain someone, the only member of the club they could reasonably call a "friend" or "acquiantance", however...
Hyoudou Issei's eyes widened in acknowledgment, his cheeks flushing, and suddenly turned back from them, breath hitching for a moment. Coughing into his fist, he responded, "T-That's um... I have no idea what you're t-talking about, I'm sorry but I have to go!"
With that said, Issei run away from them, almost tripping on a twig on the floor as the duo watched, their curiosity piqued and wanting to know why exactly Issei felt the need to be so defensive. But with so little to work with, and no one wanting to answer for them, they didn't have much to work with. Sitting down, they look up to the sun, feeling hopeless.
Luckily for them, an excuse came to them very quickly in the form of an Kiryuu Aika , coming back to the duo after watching their conversation with the Prince, having previously talked to them about this very same subject. She reasoned that she had to deliver something to Asia that she couldn't send directly, and having never entered the clubroom herself, she needed another excuse to have a pair of surrogates do the dirty work for her. The plan would go that they'd go to their clubhouse first, deliver the parcel to Asia, and... something. They would work it out, but apparently Motohama would only need to take a singular photo of the woman to make out her measurements.
When they questioned Aika about her direct involvement in this 'project' of theirs, the girl looked at them with a menacing gleam of her glasses. Adjusting them slightly, she responded, "I want fewer threats to my (social life) as possible." The other two didn't know what she actually said, to be exact, but somehow it sounded like it was threatening their lives.
Arriving at the door to the clubroom, they knocked on the door. No response. They tried again, with no luck on the draw once more. Sighing, Aika took a few steps back, prepared herself, then ran into the door, slamming it wide open. When the dust settled, they gasped, taking in what they were seeing.
Standing before them was Hyoudou Issei, prince of the school... dressing up in a Kuoh Academy girl's uniform. Just beside him was a certain Shidou Irina , helping him put the rest of the outfit on. Tinges of red highlighted bits and pieces of Issei's long hair, his face suddenly looking quite a bit feminine, most likely make-up, and a hair clip accentuating the rest of his features. Suddenly, everything made sense now, in their opinion and skewed perspective of the situation that is.
The reality was that Hyoudou Issei was very much not a man (well, not 100% of the time) but a girl. Issei didn't really go out of her way to make herself look suspicious in the eyes of her classmates, but needs were urgent at the time and didn't have much to properly explain to them. It came with the risk of revealing her physical gender, minute as it was thanks to the Kippousai spell, but it was still a risk to be avoided. Ideally she should've expected them to try and figure it out the hard way, considering her experience with the subject.
Why exactly was she being dressed up, you may ask? Well, that's fairly simple, actually. When Shidou Irina found out the whole truth, and the entire truth behind Issei's current form, she was ecstatic learning that all of the things she loved about the boy she met so long ago was not wasted. Weird as it may be, Shidou somehow convinced Issei to play dress up for her in her various female and male forms. If there was anything Issei wanted to do, it was make the most out of every interaction she had with her.
With that in mind, Issei could only stand with a growing blush, thinking perhaps they should have taken the time to keep the doors locked a bit better. Dread formed in her stomach, thinking perhaps that this was it, rumors would spread, everyone would know she was a girl the entire time despite the magic tricks doing their best to avoid such a problem. Was this how it was going to end? A secret spreading because of a bunch of overzealous classmates? Sure they could hypnotize them, make them ignore everything they've learned today, but doing that sort of thing just felt wrong.
"You..." Aika began. "You're a... a..." Aika then took a quick look at Gasper sitting in a chair behind the two, who chuckled nervously. She put two and two together and thought of the only appropriate comparison. "A crossdresser!?" She said
"Eh?" Issei replied, confused. This wasn't a line of dialogue they were expecting. A girl? Sure, that was expected. Even as Oda Kippousai, she looked sufficiently girly enough to be considered a pretty boy, but outright crossdressing? Wow. That. That didn't even come across her mind.
"Yeah! And you're standing around in that girl's uniform like you own it, Hyoudou!" Aika replied. She took a mental note to drag the perverted duo back with her, their current postures possibly telling her that they are currently Blue Screening. "Are you the hot chick that everyone keeps calling a sister of Rias-senpai?"
"I..." Issei began, but was cut off immediately.
"Don't answer that, actually. You're tall enough normally, your hair's reddening and you look girly enough right now to qualify." Facing back with a huff, she moves her arms to pull the two brain dead perverts with her, them sliding across the floor.
The doors close, Issei and Shidou now alone for the most part. Issei asked, "What just happened...?" She took a little bit of her time to adjust the skirt on her waist that fell to the ground when she wasn't focused enough. Hearing Shidou cough for a bit, she faced to look at her.
"I think you made everyone think that you were a drag queen, Issei." She shifted her head to face Issei as well, a bead of sweat rolling down her face. "Hey, at least they don't know you really are a girl," Shidou said, worriedly.
"I hope so..." For the most part, they didn't. But when the next copy of the school paper came the next week, the mystery of the College Aged Dominatrix from the Occult Research club was solved. Written down, they identified Issei as the person behind the mask, a fact that made the fangirls scream even harder