Chapter Text
The morning sun filtered through the high windows of Kimetsu Academy, painting the marble hallways in shades of gold. The murmur of students mingled with the distant echoes of teachers, a familiar symphony of a new day.
Genya Shinazugawa slid his backpack over his shoulder, his gaze fixed on the horizon of his next task. He didn't possess a distinguished or notable scent of his own; if one didn't pay close attention, they wouldn't even notice the almost non-existent aroma of watermelon.
Perhaps it was due to his status as an Enigma. Enigmas were very rare in society, and to his bad luck, he happened to be one. But unlike him, other Enigmas possessed strong, powerful scents—perfect for suppressing Alphas.
But not him. And Nemi would slit his throat if he ever tried to suppress anyone.
Therefore, his body, in its infinite wisdom, had found an adaptation for his deficiency: he could replicate any scent. Perhaps as a way to adapt to others, a way to be part of society—he didn't truly know.
A strange gift, but a profitable one.
So, he decided to start his business: replicating scents on demand.
His "business" was discreet and his clients anonymous. He received requests through a specific locker that served as a mailbox and delivered the requested objects with the replicated scent in that same spot—no questions, no names. It was perfect. And extra money was never unwelcome.
"GENTA! GENTA!" The thunderous voice of Inosuke, an Alpha with overflowing energy, echoed through the entire hallway, killing the Enigma’s meager good mood that morning.
Genya didn't stop walking, his deep voice resonating with a noticeable, forced patience. The Alpha was so close he could feel his scent sticking to the roof of his mouth. Pine and earth. It was curious; he had replicated Inosuke's scent at least five times. Who would have thought that rowdy guy would be so popular? "Inosuke, it's Genya, not Genta."
"You owe me a favor! Remember? You said you could make my scent more imposing!" Inosuke puffed out his chest in a silent challenge to no one in particular.
The Enigma sighed deeply, searching the depths of his soul for enough strength not to send the rowdy Alpha—who was blocking his path—to hell right then and there. "Inosuke, I've told you many times, I can't alter your scent, I only replicate it. And I don't owe you anything; that deal was void the moment you decided to put a dead frog on my head." He continued walking with a firm, hurried pace.
"You don't know how to accept gifts! Besides! The scent of the beast must be the strongest! It's for the sake of domination! I want everyone to know the great Inosuke is here!"
The scent of peach and vanilla reached his nose even before its bearer. Zenitsu, an Omega with palpable anxiety, poked his head through a classroom door to his right.
"We all know you're here because you're screaming, you idiot! Stop bothering people!" He let out a shriek as if he weren't bothering everyone with his own shouting right now. His eyes met the Enigma’s for a moment, barely realizing Genya was there. He couldn't blame him; Inosuke’s scent was stinking up the whole place.
"Good morning, Genya!" His voice dropped in tone slightly, a small blush on his cheeks from the yelling.
"Like a peach". He would never say it out loud, of course; he simply limited himself to responding with a nod.
He had also replicated the Omega's scent a couple of times; after all, it was a sweet, soft aroma that most people liked. That included himself, Genya liked sweet things.
"Genya, good morning!" Another familiar voice called out from his left. Tanjiro approached quickly with a smile and a cheerfulness that Genya never quite understood. The Omega greeted his other two sidekicks. Genya responded with a nod of his head as he turned to continue his way. He didn't notice that a pair of eyes followed him until he disappeared around a corner.
He quickened his pace, leaving behind the daily morning fight between Zenitsu and Inosuke and the peacemaking Tanjiro.
He had more important things to do, like the math class he was about to be late for.
Sanemi was going to kill him. He was a fool to think that being his brother would earn him any favoritism; how naive. He had lingered a bit while leaving the last commission he’d finished the night before in the locker. It had been relatively easy to do, since the person to be replicated lived with him. Who in their right mind would ask for the scent of Shinazugawa Sanemi himself, a dominant Alpha? Of course, he didn't judge his clients; now, the blue handkerchief with fish patterns—scented with brown sugar and fig—awaited its owner. An unusually sweet scent for someone of his category.
Genya had a few more yen in his pocket thanks to that.
Curiously, this was a regular request: Nemi’s scent. He suspected it was some Omega who used it during their heat, but he didn't say it.
The sound of the bell announcing the start of classes rumbled through the walls, creating a deafening echo and startling the students in the hallways. He hurried his step, breaking many rules about not running in the corridors, but it wasn't as important as reaching his destination. His sprint ended when he turned left and almost crashed head-first into the closed door of his classroom.
Genya was dead.
After a scolding from his brother, he made it through that class and the next without incident until lunchtime.
The bell and the midday sun signaled the end of the first half of the school day. All the students rushed out of their classrooms in search of something to eat; some decided to stay inside and eat their bentos alone or accompanied by classmates. Even the teachers took their well-deserved break during that hour and a half.
Genya hung his bag on his right shoulder and walked toward the courtyard to meet the Tokito twins. Despite what others thought, he wasn't a core part of Tanjiro’s group; they got along well and were friends, but it wasn't his primary friendship—though Tanjiro was a bit closer than the others. That spot belonged to the Tokito twins. He didn't know how his friendship with both Omegas started; he only knew that one day they stuck to him and never wanted to leave. At first, Yuichiro was a bit more reluctant to be around him because of his Enigma status, but after a while, he set his bitterness aside.
The sun hit his entire body the moment he stepped out of the building; the rays illuminated the whole campus at that hour. The weather was hot, typical of spring. When he saw two identical heads of hair under one of the trees, he thanked Buddha; he couldn't stand the heat a moment longer.
"Genya!" The first to greet him was Muichiro, the more "sociable" of the two. His scent was like light lotus flowers, an aroma so soft one had to pay attention to notice it. "We were waiting for you. What did you bring for lunch?"
Genya reached the tree where they were located; the shade was an instant balm for his body. "The usual. Roasted vegetables and some tofu."
Yuichiro, leaning against the tree trunk, barely looked up from his bento. His scent was the opposite: dry leaves and black tea—a camouflaged Omega who projected an air of harshness to keep meddling Alphas at bay. "How boring."
"Not everyone lives on pork, Yuichiro." Genya sat down, causing some leaves to crunch under his weight. He opened his own box. Eggplants, carrots, and tofu. Muichiro slid closer to the Enigma, inhaling deeply, the light perfume of a cold breeze intensifying.
"Today you smell like fresh watermelon" he let out a soft sigh. "I like it." It wasn't the first time Muichiro had done that, but it always made Genya a little nervous. After all, an Omega sniffing an Alpha—or in his case, an Enigma—was something very strange and intimate.
Surprisingly, Yuichiro nodded.
"Yes, it's peaceful." His expression relaxed slightly, and Genya noticed with his hyper-senses that the note of vinegar in Yuichiro's scent softened slightly. "Not like others," he finished with a hint of resentment in his voice, likely referring to some noisy Alpha.
The atmosphere filled with the murmur of other students sharing space near them, distant laughter, and the clinking of cutlery. But under that tree, a bubble of calm surrounded them. Genya’s watermelon scent, so imperceptible to himself, seemed to soothe the twins.
"Will you scent us a little, Genya?" Muichiro cut the silence, tilting his head with pleading sea-green eyes and voice. "Just a little."
Genya raised an eyebrow. This was the part he didn't fully understand about his Enigma status or whatever it was that attracted Omegas and some Betas. To him, it was subtle, almost a rumor, but to them, it was a breath of tranquility and security. The same thing happened with his younger siblings and some other Omegas, like Zenitsu and Tanjiro himself. "Sure."
Yuichiro closed his bento to move closer to Genya, almost brushing shoulders—a somewhat unusual contact coming from the distant twin. Muichiro curled up on the other side, more confident, resting his head on Genya’s shoulder.
Genya’s Enigma was an underground spring, not a torrent like the others. It didn't mark, it didn't dominate; it only comforted. He took a deep breath, releasing a slow exhale. The air around them thickened very slightly; only noticed it if paid enough attention.
Both Omegas absorbed the scent, relaxing instantly—shoulders dropping and muscles becoming less tense. Genya felt Muichiro’s lotus flowers become denser and sweeter, a sign of deep relaxation, while Yuichiro’s dry, dense smell almost disappeared, leaving only the underlying and barely perceptible sweetness of an exhausted Omega.
Genya watched their faces; peace seemed to have reached them.
"Strange," he thought. But if it gave them a bit of tranquility, who was he to refuse?
"Ah, much better." Muichiro let out a soft sigh. Yuichiro grunted in agreement. Both Omegas pulled away from the Enigma to continue with their lunch. Genya opened his own bento again, welcoming the tofu that awaited him.
The lunch hour ended a while later with the bell buzzing again. He said goodbye to the twins and headed to his next class. Luckily, there were only two more left and he could go home.
The bell tore through the air, a metallic groan that announced the end of the torment. Genya dragged himself toward his commission locker—locker number 22 in a forgotten hallway of the old part of the school. The metal felt frigid under his fingers.
The presence of a plain, unmarked black envelope, along with an emerald green silk handkerchief, didn't surprise him. He picked it up with his fingertips and opened the flap without haste; he already knew what it contained: another order. His eyes scanned the unknown calligraphy. The note had no sender, as usual.
"Eh?" The sound escaped his throat, raspy. Confusion and a prick of curiosity forced him to reread the note over and over. It was written with a neat hand, asking for a scent he had never been requested to do before. That, in itself, was strange.
The Omega in question possessed one of the most popular scents—if not the most popular—among the students of the Academy. When he started his little "business," he thought Kamado Tanjiro’s scent would be the most requested: the essence of kindness and comfort. He was wrong. His popularity was such that no one needed to replicate it; everyone knew it and loved him just as he was. And replicating it would be like a way of "profaning" him, according to what he had heard.
Double strangeness: that scent was one of the most unique he had ever witnessed. Warm, fiery, but at the same time humid and fresh. It was a contradictory complexity that Genya admired and feared. He could isolate each layer: sweet green tea, firewood, and a trace of petrichor after the rain. But the final layer—the Sun—was a pure, emotional heat that he didn't think he could synthesize.
The dark ink on the light paper said bluntly:
"Omega, Kamado Tanjiro. I'll pay double. Sample included."
The Omega of the constant smile.
Who was he to judge his clients?
His hand took the sample that was attached: a small and green piece of fabric, warm and familiar. He took a soft breath of the handkerchief, and a light, sweet aroma—indeniably Tanjiro’s—bloomed in the air, mixed with a faint touch of water.
The scent vividly reminded him of the times Tanjiro had smiled at him in the hallways, that warmth his own essence lacked. He tucked the handkerchief into his pocket, feeling the slight brush of the fabric against his skin.
"Double?" he whispered. His voice sounded louder than usual in the silence of the abandoned hallway.
The challenge was accepted.