Yoshiwara Red-Light District, also known as Yoshiwara Yukaku, was located in Tokyo's Taito Ward.
During the day, it was indistinguishable from countless other ordinary streets in Tokyo.
But when night fell, it seemed to awaken, radiating a dazzling, intoxicating brilliance.
As for why it was called the "red-light district"—simply put, this bustling street was composed of countless pleasure quarters.
Nearly everything here was built to serve these establishments, which were, in essence, brothels.
According to Uzui Tengen, Yoshiwara was a sleepless land where countless men and women's love, hatred, vanity, and desires converged.
The most common sight in the red-light district was undoubtedly the beautiful geisha.
Most were girls from impoverished families, forced—whether willingly or unwillingly—to sell themselves here for survival.
To fill their stomachs and clothe themselves against the cold, they had no choice but to engage in work that others might scorn.
However, let's not assume all these geishas are women of ill repute.
In truth, if not driven by desperate circumstances, no one would willingly sell their body.
There will always be people in this world who have no choice but to endure hunger and cold.
Of course, becoming a geisha doesn't mean being trapped in endless darkness forever.
There are hierarchies among geishas too—those of higher status don't need to sell their bodies.
With exceptional beauty and extraordinary talents alone, they can live quite comfortably.
These high-ranking geishas pursue far loftier goals than ordinary ones.
With enough luck, they might even attract wealthy merchants willing to buy their freedom, allowing them to shed this identity and live normal lives.
At the pinnacle of the geisha world stands the courtesan, known as the "flower queen."
Those who reach this level are invariably the cash cows and prized possessions of the brothel madams in the red-light district.
Yet beneath this dazzling, intoxicating facade—where darkness thrives most easily—who knows what evils, or even... demons, might lurk beneath the seemingly glamorous surface of the red-light district?
"Hey there, handsome~ Come take a look~"
"Blondie, you're so cute~ Come chat with onee-san~"
"Oh my, that young man looks so fierce~ That scar on his face is terrifying~"
"What's with the wild boar?"
At the bustling edge of Yoshiwara's red-light district, a group of unusually dressed travelers with conspicuously bulging waists—as if carrying swords—stood out.
From the brothels lining the streets, countless heavily made-up geishas enthusiastically called out to potential customers.
Naturally, the Demon Slayer Corps members drew particularly enthusiastic attention, though the recipients of these greetings were far less enthusiastic.
Uzui Tengen strode at the forefront, his towering figure adorned with gemstone accessories that glittered brilliantly under the district's multicolored lanterns.
Unfazed by the geishas' fervent calls, Tengen remained utterly composed.
Shinichi followed behind Tengen, curiously surveying his surroundings.
To be clear, he wasn't enticed by these heavily make up women—they couldn't hold a candle to even Shinobu's fingertip in his eyes.
But since it was his first time in such a "legitimate" pleasure quarter, he couldn't help feeling somewhat intrigued.
Compared to Shinichi's curiosity and Tengen's indifference, Shinazugawa Sanemi trailing behind them was purely irritated.
The women's gazes made him deeply uncomfortable, and the scar on his face unconsciously twisted into a fiercer expression.
"What kind of dump is this? What's wrong with these women? Why are they all staring at me?"
Bringing up the rear behind the three Hashira were Tanjiro, Zenitsu, and Inosuke, following closely.
Tanjiro and Inosuke were fine—or perhaps too innocent to fully grasp what the red-light district truly was—so they remained largely unaffected by the geishas' advances.
Zenitsu, however, was another story.
Zenitsu's face had already turned bright red, and the calls from the young women made his steps unsteady.
"Ah~ So many pretty ladies~"
"Zenitsu! Zenitsu! You're wandering off—wait up!"
Seeing Zenitsu's increasingly erratic steps, Tanjiro quickly grabbed his sleeve to prevent him from drifting away like a fool.
Suddenly!
Something seemed to be happening up ahead, as many excited pedestrians began converging in one direction.
The bewildered Demon Slayer Corps members found themselves swept along by the crowd toward the commotion.
"It's Courtesan Koinatsu from Tokiwaya!"
"Wow! She's absolutely stunning! If I could just have one meal with Courtesan Koinatsu, I'd be willing to live in a villa!"
"How greedy can you be? Wanting both food and lodging?"
"So beautiful~"
Amidst the chaotic chatter around him, Shinichi frowned and pushed past several obstructing pedestrians.
Then, a peculiar procession came into view.
How to describe it?
To Shinichi, this procession seemed utterly bizarre—several men dressed in gaudy colors accompanied young girls carrying various items like lanterns and boxes.
At the center was an exceptionally beautiful woman wearing luxurious kimono, holding what appeared to be a folded futon?
She walked slowly in a distinctive manner, balancing on wooden sandals that were at least ten centimeters high.
The entire procession seemed to revolve around this radiant, stunning woman at its core, moving forward at a leisurely pace.
This must be the Courtesan Koinatsu everyone was talking about?
"A courtesan procession from Tokiwaya? That's one of our suspected targets this time," Uzui Tengen remarked, arms crossed beside Shinichi.
Shinichi took another look at Courtesan Koinatsu at the center of the procession.
Well, one had to admit—being called a courtesan wasn't for nothing.
This woman named Koinatsu was truly beautiful, even with heavy makeup and those cumbersome-looking clothes.
No wonder the onlookers were so excited.
"The outskirts of the red-light district are already this lively? This investigation might prove quite challenging," Shinichi said to Tengen.
Nearby, Sanemi glanced at the courtesan procession and scoffed.
"Challenging or not, we have to investigate. Though I doubt any Upper Moon lurking in a place like this could be worth much."
Uzui Tengen surveyed their surroundings decisively.
"Let's move. We're too conspicuous right now. We'll infiltrate the red-light district after proper disguises. Hey! You three brats, get over here now!"
The "brats" Tengen referred to were, of course, Tanjiro and his companions.
This investigation plan of Tengen's also relied heavily on the three of them.
"Disguised infiltration? What kind of disguise?" Sanemi asked skeptically.
Shinichi also turned to Uzui Tengen, awaiting his answer.
With a slight smirk, Tengen replied casually, "The disguise is naturally... dressing up as geisha to blend into the red-light district."