清楚系双子アイドルの裏事情　～俺だけが知る淫らな二人～（Seisokei Futago Idol no Ura Jijou ~Ore Dake ga Shiru Midara na Futari~）

Back in the day, there were twin sisters who lived nearby. They were younger than the protagonist, and the three of them got along really well.
The twins adored him, and since they were all curious about "adult stuff," they often played around in ways that were… let’s just say, a little inappropriate.
But eventually, the twins moved far away, and they lost contact.

Years later, the protagonist—now struggling to find a job—saw the twins on TV. They had become wildly popular rookie idols, the kind of fresh-faced, "pure" duo everyone loved. Watching them shine under the spotlight, he felt a strange, indescribable loneliness. They were famous idols now, and he was just a jobless nobody. How had the gap between them gotten so big? And wait… hadn’t he done that kind of stuff with them back then?..

To make matters worse, he’d just gotten another rejection letter from a company he’d applied to.
Feeling sorry for himself, he started drinking heavily in the middle of the day.
In a moment of weakness, he decided to call a prostitute.
But just as he was about to place the order, there was a knock at the door.
Too drunk to think straight, he didn’t question why the "prostitute" had arrived so quickly.
When he opened the door, he was shocked to see his childhood friends—the twin sisters, now famous idols—standing there.
They explained that they were filming a segment for a TV show where they visited people who had been important to them in the past.
But the protagonist, still drunk and convinced they were the prostitutes he’d ordered, pushed them inside and forced himself on them.

When he woke up the next morning, the twins were lying next to him, their innocence lost, clinging to him as they slept.

[Translated from dlsite]