There was a girl named Kogane Yui in the ordinary City O. The girl was cheerful and well-loved by family and friends. Thanks to her friendly demeanor and good grades, she was also popular at school. This year, she finally enrolled in her dream college, starting anew as a freshman.
Yui had a secret—one she held immense pride in. She was a magical girl fighting for the city's peace. It has been a little over two years since she was scoured by a mascot and took on the name of Magical Helleborus. Although life as a magical girl was very busy, nothing could triumph over the joy of transforming and helping people. Except... she had another secret—one she held closer to her heart than anything else. A secret so devious and shameful that she could not even tell Rui, her cherished younger twin sister.
A few years prior, when Yui was an ordinary high schooler, she had the misfortune to be involved in a terrorist act by The Legion's commander. Back then, the dashing figure who came to her rescue was none other than the kind and graceful Osbeckia. Yui quickly became infatuated with her, gradually seeing herself sinking into the rabbit hole of magical girls.
Yui's admiration for Osbeckia was well-known and justified, though nobody realized that her simple teenage idolization of the magical girl had long turned into an obsession. Slowly, seeping like muscus, it became viscous and sticky, dyeing Yui's mind a dangerous color.
Truthfully, being able to wield magic and fly in fluttering skirts was only half... no, a third of the reasons why she became a magical girl. The rest? Well, as a junior magical girl, she could finally get closer to her crush, Magical Osbeckia! Over her two years in this profession, she had accumulated a good amount of goodwill from Magical Osbeckia, as well as the real person, Kisaragi Moeka, putting herself in a favorable position.
Of course, Yui was heartbroken when she heard that Moeka had gotten herself a girlfriend, but she believed she still had a chance! Even if she did not have a chance, she would create one for herself. After all... Yui loved Moeka more than anyone in the world.
'Ah... how am I supposed to hold this in, senior...?'
Even now, as Yui browsed the collection of Magical Osbeckia's images and videos, she could not help but feel her heart racing. Lately, she had been exchanging information with a user named Liliac225 on the famous forum, BananaBoard. As the top contributor and moderator for n/Osbeckia, RadiantStarch4, Yui thought her understanding of the magical girl was the most profound, yet this mysterious user was surprisingly insightful.
Though Liliac225 was rather lewd in the comments, Yui decided she had nothing to be jealous about. The opponent was an anonymous nobody, and she was Osbeckia's own junior. So, she could have Liliac225 provide her with juicy Osbeckia intel without worries.
Besides... it would be a lie to say that Yui was not interested in her senior's body. She liked to delude herself into thinking her love was pure, but virtually no one could resist someone like Moeka, who was both alluring and sweet. Yui herself became an Alpha during the incident that shook the world, which she did not pay much attention to at first. But perhaps it was destiny itself speaking to her; she now had the chance to ask Moeka out directly.
So, on the excuse of needing to calm her heat cycle, Yui texted Moeka.
'Well... I'm not really lying anyway.'
After witnessing that silver-haired pervert taking advantage of Moeka right before her eyes, Yui was both furious and aroused. If she kept daydreaming of those scenes like now, an accident might actually occur.
''Sis, where are you going?''
''...I have something to do.''
''Want me to go with you?''
''It's fine.''
Yui finished her preparations in minutes after receiving Moeka's affirmation. Leaving her innocent twin sister behind, she bolted out of her house.
The rendezvous spot was quickly decided to be the chess club at Orion University. After all, it was designed for their upcoming activities. Although Yui would like to take Moeka on a real date, she did not have sufficient reasons at the moment.
''Hoo...''
After settling nervously in the club room for a while, Moeka finally arrived.
''Senior—''
But as soon as the person stepped into the room, Yui froze. In less than a second, she sensed a thick scent of another Alpha clinging to Moeka's body. Unconsciously, she gritted her teeth.
'They must have done it a lot, huh...'
This raging flame in her heart, and this bitter jealousy—all proof of her intense love for Moeka. Yet... Yui also knew she had no right to challenge this 'injustice.'
Meanwhile, Moeka did not notice any anomaly, ''Hi.'' She greeted casually, ''How have you been?''
''...I'm doing great, senior.'' Yui replied, ''Just... my pheromones have been a little unstable. I'm afraid it would affect someone...''
''I see.'' Moeka nodded, ''Shall we begin right away, then?''
''U-Understood!''
Yui sheepishly followed Moeka into the bed chamber. It looked rather comfortable, though a little cramped, but even that seemed intentional. Yui could only distract herself by admiring the interior of the room while Moeka removed her outerwear, leaving herself with a skirt and a simple shirt.
''Come here.'' The Omega called, sitting on the edge of the bed.
''Y-Yes!'' Yui obliged, ''Um... what should I do now...?''
Moeka glanced at the fidgeting girl right before her. Up close, she was unexpectedly tall and imposing, Moeka thought. At the same time, a little cute, unlike that silver-haired pervert. But... what was this atmosphere? They were not shy newlyweds.
Moeka cleared her throat, ''Do what might get you excited, then you can mark me.'' She added, ''No kissing, no excessive touching.''
''I-I understand!''
Mustering every bit of her courage, Yui gently put her right knee on the bed, half-straddling Moeka. Relishing in the Omega's delicate beauty, Yui approached, as if entranced, pulling on Moeka's collar.
''Ah, wait...! This area is a little...''
''...''
Although Moeka quickly covered it, Yui had caught glimpses of conspicuous red marks on the Omega's milky skin. They were... hickeys. Almost in an instant, her reasoning snapped. An unfathomably cold look descended on her face, though it only lasted for a brief moment.
''...?!''
Moeka nearly jumped as a chill crept up her back, but she never realized it was from the innocent-looking junior in front of her. A short silence ensued, but finally, Yui leaned down, nuzzling her face against Moeka's neck, hugging her soft, warm body possessively as if wanting to rub her scent all over it.
Then, as Yui pushed forward, both fell onto the bed. Moeka was initially startled, but since it was a mere hug... she decided to reciprocate. Gaining confidence, the little Alpha got bolder. She slowly trudged downward, burying her face in Moeka's pillowy chest. The softness, the bounciness, the milky scent—it was nothing short of heavenly.
A tingle marked Yui's teeth. She wanted to leave a mark on this person.
So, leaving it to her instincts, Yui took Moeka's small, dainty hand and pressed her lips against its back. Although they were lying on a bed, the gesture was unexpectedly romantic.
Yui got lost in the fantasy of putting a ring on Moeka's hand for a while, but she eventually moved upward, gently biting down on Moeka's forearm.
''Ah...''
A little mark, for a little yandere.