The sounds from the kitchen were a special kind of torture for Yuna and Ayane: The rhythmic thump-thump-thump of a knife on a cutting board, the sizzle of oil hitting a hot pan, and worse, much worse, Mika's soft musical giggle floating through the apartment.
It was a symphony of domestic bliss, and Yuna wanted to burn the entire orchestra to the ground.
She sat on the living room floor, surrounded by a sea of cosplay fabric, a thunderous expression on her face. Across from her, Ayane was calmly sorting through a pile of lace with unbothered grace.
"Sounds like that bitch is enjoying herself in there," Yuna snarled dangerously. She picked up a piece of deep purple fabric for Shinobu's haori, twisting it into a tight, angry knot.
Ayane let a pink slab unspool through her fingers lazily. "You know," she began with an amused purr, "despite calling her that, you were surprisingly protective of Mika-chan back there at the supermarket."
Yuna, aggressively sorting plaid fabric for Mika's costume, didn't look up. "Protective? Don't be an idiot," she growled. "I just hate seeing pathetic bitches win. That Emi girl was annoying."
"Right," Ayane drawled, her smile audible in her voice. "It had nothing to do with the way your precious big bro was holding Mika's hand like she was some damsel in distress who needed saving. Or the way Mika glanced at you when she didn't know where to look."
That hit a nerve. Yuna's hands stilled. "At least Mika knows her place," she shot back with saccharine venom. "You're the one who just showed up and started taking him away from us."
"And I'm winning, by the way," Ayane countered smoothly. She sauntered over to where Yuna sat with fluid confidence. She leaned down. "What's your official title again? 'Main Wife'? Sounds a little domestic and boring for a stepsister."
Ayane chuckled throatily. "Remember last time? He even promised to impregnate me." She idly traced her belly in a deliberate gesture. "That has to count for something in the harem hierarchy, miss Main Wife?"
"There is no 'hierarchy' for you to climb," Yuna shot back, finally looking up with eyes like ice chips. "You're just a guest star, a one-off OVA character. I'm the main series heroine, the one he's been fantasizing about since middle school."
The words were a direct hit. Ayane's smug smile faltered for just a second. "She's good," Ayane thought with a flicker of genuine respect. "Vicious, but good."
"Oh, honey," Ayane purred, recovering with practiced grace. "You're the stepsister, yes. But you're not the heroine, just a forbidden, slightly pathetic route in a B-grade eroge. I'm the hot, mysterious transfer student who shakes up the plot."
The volley of insults was sharp and surprisingly accurate. They stared at each other, chests heaving.
Then Ayane's expression softened slightly. She picked up the butterfly-patterned fabric Yuna had chosen for her Shinobu cosplay. Her long fingers traced the delicate design.
"This silk is actually really good quality, and the color matches," she said with surprising sincerity. "You have good eyes. Must have done a lot of research?"
Yuna was taken aback. She'd been prepared for a fight, for a full territorial war. Not for a genuine professional question from a cosplay nerd. For a moment, she just stared, her brain buffering. "Of course," she finally muttered grudgingly. "Unlike someone, I take my cosplay seriously."
Ayane nodded with new respect. She picked up the unstyled Mitsuri wig. "And my wig is still a nightmare," she said with professional sympathy. "It's going to be a bitch to style and dye this..."
The unexpected camaraderie was strange and disorienting. Yuna felt her defenses lower slightly. "Your fault for choosing to cosplay her!" she grumbled. "But it'll be worth it when he sees it." The admission hung in the air.
Ayane was silent for a moment. "You know," she began more softly, less performatively. "Sometimes I wonder why we do this." She gestured at the expensive fabric. "Spend all this time and effort just to impress one stupid, fat pig."
They were silent for a long moment, the only sound the distant sizzling from the kitchen. They had just laid their deepest insecurities bare and found unexpected common ground.
Then Ayane sighed. The fight drained out of her, replaced by weary curiosity. "Seriously, though," she said, softer now, stripped of seductive purring. "How does this even work?"
Yuna stared suspiciously. "What do you mean, 'how does this work'?"
"I mean this," Ayane gestured vaguely around the room at the cosplay materials and sounds of domestic bliss from the kitchen. "I gave him this big dramatic speech about a 'hostile takeover,' but the truth is I have no idea what the fuck I'm doing."
She looked at Yuna, completely devoid of her usual teasing. It was raw, honest, and desperately vulnerable. "You're his stepsister. That's a level of fucked up I can't even begin to compete with. So how do you handle it?"
Yuna sighed, then finally looked up. Her eyes were stripped of their usual fire, just tired. "Why are you even here? You're cool, you have a nice figure. You could have any guy in your college, without any of this harem bullshit. Why my stepbrother? Why this mess?"
The genuine question caught Ayane off guard. Her smirk faltered. She sighed and sat down on the floor amidst the fabric, pulling her knees to her chest.
"Because he's an idiot," Ayane said surprisingly softly, without her usual predatory purr. "Because the handsome guys are boring and the rich guys are assholes."
She picked up a stray thread, twisting it around her finger. "He's the only person who gets my obscure Gundam references. The only one who knows the difference between a Zaku I and a Zaku II. And he makes the best fucking karaage I've ever had."
She looked at Yuna, and for the first time, Yuna saw not a rival but just a girl. A girl who was just as lost as she was.
"I saw you guys," Ayane confessed quietly. "At the cafe. And you were bickering, and he was being a dumbass, and you were being a psycho bitch, but you all looked so happy."
A small, sad smile touched her lips. "I saw happiness, and I wanted in." She looked at Yuna with surprising sincerity. "I didn't want to steal him from you. I just wanted to be part of it."
Yuna stared, conflicting emotions warring inside her. She wanted to hate her, to call her a manipulative slut. But the raw honesty in Ayane's voice was disarming.
"So you're just as pathetic and desperate as the rest of us," Yuna finally muttered in grudging acceptance. It was the highest compliment she could give.
Ayane laughed with relief. "Yeah," she said. "Pretty much."
A comfortable, companionable silence settled over them. In that silence, a fragile unspoken truce formed. "You know," Ayane whispered conspiratorially. "She's the one we really need to worry about."
Yuna didn't have to ask who "she" was. A guttural growl rumbled in her chest. "The manipulative heartless bitch," she muttered.
"She's playing a completely different game," Ayane agreed thoughtfully. "You and I, we're fighters. We're loud and obvious. But her, she's a sniper. She waits, she observes, and then she takes the perfect shot."
"She got him to agree to the morning run," Yuna said dangerously. "And they even did sexting behind my back. That's next-level."
They looked at each other in silent acknowledgment. They weren't friends, probably never would be. But for now, they were allies, united by a shared love for the same clueless, perverted man, and shared fear of the sweet, innocent, terrifyingly competent girl in the kitchen.
Just then, Mika returned from the kitchen, completely naked behind Yuna's tiny pink apron. The fresh dark hickeys on her neck were a blatant declaration of war.
"Ayane! Yuna!" she called out cheerfully. "Dinner's ready!" She walked into the living room, showing off her naked apron and bruises.
"Holy shit," Ayane muttered, eyes wide as they fixed on the hickeys.
Yuna dropped a bolt of fabric on her foot and didn't even notice. "What the fuck," she whispered brokenly, "did you do to my apron?"