Panties.
They are women's form-fitting underpants. Typical components include an elastic waistband, a crotch panel to cover the genitalia (usually lined with absorbent material such as cotton), and a pair of leg openings that, like the waistband, are often made of elastomer.
While the school has no standard for what kind of panties a female student should wear, most of them would simply wear something normal such as simple white panties, or those who had limited money probably used the previous panties that they wore in their young time as their bodies didn't grow much.
While it was strange, panties were the last item of clothing that people usually bought. While people could buy shirts or pants a few times a month, they would only buy panties once in a few years, showing how rare it was for this piece of clothing to be bought by someone, especially for a man.
However, for a woman, it was different as there were varieties, and many women loved to be playful with their choices of underwear, whether it was its color, shape, patterns, or even materials.
Still, considering Ririsa's personality, Masa felt like she would be wearing something plain, especially when he knew how this girl lacked an understanding of fashion.
The fashion in anime and in reality was different.
The clothes worn by the heroines in the anime and manga were usually the fantasy of what every male wished them to wear, so it was impossible to use those clothes as a reference for what to wear.
If it were normal, people would be looking at social media or magazines to learn what kind of trends or suitable clothes one should wear. Still, if it was too difficult, then one should just buy clothes that were worn by the mannequins in the clothing stores as they were chosen based on professional arrangement.
Regardless, Ririsa had zero knowledge of all of that, and her head was filled with either anime, manga, games, eroge, erotism, cosplay, and many other techniques to further hone her skills in her hobby, so Masa was surprised when he saw that she had chosen such panties.
Yet, while he had to say much, he had to say this sudden stun where she just dropped her skirt, showing him her plump, healthy hips and round buttocks that were wrapped in such lewd panties; he felt... his breathing became harder.
Her sensitive area that should be hidden was hidden by the panties, yet as they were lace type, it was almost seen through, which made him able to see the smoothness of her untouched slit.
Noticing his gaze that was all over her lower body, Ririsa squeezed her legs tighter, yet instead of stopping, she became even bolder, unbuttoning the shirt of her uniform one by one, which slowly displayed the haughty breasts that were also hidden under a well-matching white lace bra.
Still—
"...I know that it might be late to say this, but... do you have to wear such detailed underwear?"
The Broken Angel.
This was the doujinshi created by Eriri based on the story of Valkyrie Battlefield and Angel Paratroopers, where the character, Liliel, the heroine that was adored by Masamune Okumura and Ririsa, came from.
'Okumura...'
Somehow, Masa wondered what would happen to Okumura as he knew that it was impossible for him to let Okumura see Risisa in a lewd form. At the same time, it was something good that Okumura might not see Ririsa, especially with how lewd this girl was.
More importantly, Masa was sure that Ririsa was the type of girl who felt good when she gained the attention of others.
Being praised, favored, and worshipped by many men.
This was how some women felt that they existed, were happy, and might even become the reason why they existed.
Frankly, this type of woman was the worst type that one should date, considering how they might expose their vulgar photos to the public, letting many men use them as a source of masturbation.
Nevertheless, as this girl was a heroine, and Ririsa also understood the ins and outs of the industry... no, Masa was sure that this girl didn't think at all, yet this was how most people. They only saw the dazzling stage of people who were favored by many as they dressed in cosplay, but the hardship that came from popularity wasn't something that one could imagine, especially if your information was discovered.
In a world where all people felt like they died despite being living, the existence of those people that gave them a light was like a pillar of support, or even worse, a god.
If those people still had common sense or believed in a certain moral value, religion, or something else that taught them what was bad or good and even understood the law to a general level, then it was okay.
While it was surprising, many people lacked common sense, whether it was due to their family, environment, mentors, or many other things.
Regardless, inwardly, Masa didn't really want Ririsa to walk into the path of making ROM despite it being her wish.
Being a model was one thing, but being a cosplayer, wearing costumes that were illustrated based on raising a man's libido, then selling those photos to lonely men...
If Ririsa was a stranger, Masa wouldn't care, but as she was his junior, he knew that he had to give her proper care, teaching her lack of experience that sometimes, she shouldn't be so silly that she would show her what it meant to wear such a lascivious clothing in front of a healthy man.
Still—
"Of course!"
Hearing his question, Ririsa answered fervently, "Those are the underwear worn by Liliel on the "Broken Angel" in chapter five! Those white lace underwear are something that I love the most! They are drawn so perfectly that sometimes, I think my god, Kashiwagi Eri, bought those underwear, owned them, wore them, so he could perfectly understand the mind of Liliel when she was told to wear such vulgar, dirty underwear when she was on a mission with Alford-sama before she goes out with that guy who toys and messes with her body!
"Senpai, can you feel those feelings? How did Liliel feel, who was ordered to wear such vulgar underwear during an important mission with the man she loved, as there was a chance Alford-sama or others would discover that she wore lewd underwear?!"
Hugging her petite body tightly, which caused her prominent breasts to swell even bigger, Ririsa's body trembled with excitement. "Ah... it was so exciting~!"
"..."
Watching Ririsa's morbid obsession, Masa thought that this girl was impossible to be cured anymore.