Seeing Sakura so focused and attentive, Kiyohime felt an unexpected sense of accomplishment.
"Love Guide Rule Number Two—the second most important principle is… Be wary of the homewrecking cats!"
"Homewrecking cats?" Sakura tilted her head, repeating the unfamiliar term in confusion. She was still too young to grasp the complexity of such phrases.
"That's right! The seductive vixens who sneak in when you're not looking!" Kiyohime nodded solemnly.
"To give a simple example—around Su Mo-sama, that would be Saber!" Hearing that, Sakura's eyes blinked with confusion.
"You mean... I should be wary of Okita-neesan?"
"But… Okita-neesan is really kind to me. And if she were with Su Mo-nii… I think I could accept that." Sakura genuinely liked Okita Souji and didn't want to treat her as a threat. In fact, if possible, she didn't mind the idea of being with both of them. That sentiment left her a bit conflicted. Seeing her hesitation, Kiyohime shook her head gently.
"I understand what you're feeling, Master," she said patiently. "But with Su Mo-sama's character, I highly doubt we're the only ones in his life." Now that she had a good idea of how the faction was structured, Kiyohime saw it clearly. Her little Master was someone Su Mo had rescued from the depths of despair. Saber was a Servant who had been by his side for some time. They were close, certainly, but their acquaintance was recent.
But a hero like Su Mo—he must have saved many others over the years. Girls with connections to him would not be in short supply.
"Come to think of it…" Sakura nodded slightly. "Su Mo-nii did mention having several older sisters back home…"
"There you have it," Kiyohime clapped lightly. "You and I are the kind of girls who care deeply about how our partner feels about us."
"In other words, even if Su Mo-sama has other girls around him, what matters most is that he loves you the most, am I right?" Despite her yandere reputation, Kiyohime was surprisingly open-minded about harems. What she couldn't stand were lies. As long as her lover was honest with her, she could tolerate sharing him. Sakura didn't have such a strong aversion to lies, but thanks to her affection for Okita, she wasn't exactly opposed to the idea of multiple partners either. And so, she nodded slightly.
"Mm!"
"That's why earning Su Mo-sama's affection—becoming the girl he loves most—is the true goal," Kiyohime declared proudly, despite never having been in a real relationship herself.
"That's also why I told you to beware of other girls. Because love is a battlefield—and it's even more ruthless when it's between girls."
"That means you must be extra careful around your rivals. Any girl who gets within ten steps of Su Mo-sama is a potential threat you must watch carefully!" Kiyohime finished her advice with a flourish.
Sakura mulled over her words for a moment. Just as Kiyohime puffed out her chest, expecting praise for her wisdom—
Sakura gave her a sidelong look and said softly, "Speaking of girls within ten steps of Su Mo-nii… that would be you too, wouldn't it, Berserker?"
This… was the definition of "learning applied immediately."
Even Kiyohime hadn't expected this outcome. Her own student was now looking at her with wary eyes. She gave a half-laugh, half-cry expression.
"H-How could that be, Master?! There's no way I would try to steal your beloved!" Hearing that, Sakura relaxed a little, though her worry didn't disappear completely.
"But Berserker, you're so pretty… you have a great figure, you're mature and dependable, and you can help Su Mo-nii with so many things…" Her voice trailed off. The doubt still lingered.
"Well, I'll take that as a compliment," Kiyohime chuckled awkwardly. "But please rest assured, Master. I would never do something like that!"
"I'm your Servant. I'm here to support your love, not compete with it."
To prove her sincerity, Kiyohime patted her chest with pride and added, "Just wait, Master. When Su Mo-sama gets back, I'll help create the perfect opportunity for you two to be alone together!"
"R-Really?!" Sakura's eyes lit up with delight.
"Thank you, Berserker—no, thank you, Kiyohime-oneesan!" Her bond with Kiyohime had deepened, and her affection slipped naturally into a more familial nickname. Between the two girls, a strong and sincere friendship had quietly formed.
"Fufufu~ Just wait, Master!" Kiyohime grinned with confidence.
At that moment, the sound of knocking came from the front doors of the Matou residence.
"Su Mo-nii!"
Sakura perked up like a startled rabbit and bolted for the entrance. She put on the sweetest smile she could muster and pulled the door open.
"Welcome ho—"
Her greeting came to a sudden halt. Standing at the doorway was Su Mo, but in his arms was a little girl she didn't recognize. At his side stood a mature-looking woman with white hair and red eyes.
Sakura stood frozen. What… is this situation?
Kiyohime just told her to beware of love rivals…
And now two of them had shown up at once?!
A big one and a little one!?
But while Sakura was still trying to process the shock, the little girl's eyes sparkled when she saw her. "You're… Sakura-oneesan?" With a squeal of excitement, Illyasviel jumped down from Su Mo's arms and threw herself at Sakura.
"Baby Sakura-oneesan is so adorable!!" She giggled as she nuzzled into her, rubbing her cheeks with affectionate energy. To say she was enthusiastic would be an understatement. The scene unfolded so abruptly that Sakura, still caught in Illya's tight embrace, temporarily gave up on trying to think at all. By the time her brain rebooted, everyone was seated in the living room.
After Su Mo's brief explanation, Sakura and Kiyohime finally understood what was going on.
"So, Miss Illyasviel is Su Mo-sama's daughter… from the future?" Kiyohime murmured, stunned as she turned her gaze toward Irisviel. Shock washed over her entire face. W-Why… Why did it turn out like this?! Could it be… even with her love guide, Master still failed to become Su Mo-sama's official partner? And instead, the mysterious white-haired woman—who had shown up out of nowhere—ended up winning?
Why?! Just because she has white hair?! Su Mo-sama wasn't even a white-hair fanatic!
…Probably.
This wasn't how it was supposed to be! Kiyohime's love guide was a collection of her finest thoughts, painstakingly compiled over who knows how long. How could it fail? How could Master be so useless?! With that thought, Kiyohime turned to Sakura with a look full of disappointment.
"Master, this is because you didn't properly follow my love guide."
"That's why the future turned out like this. That's why you lost."
"Otherwise, it should have been you and Su Mo-sama who had a daughter traveling back through time!" She leaned in and whispered conspiratorially to Sakura.
Sakura's little face instantly turned red. Half of that was from embarrassment at the mere thought of having a daughter with Su Mo-nii. The other half… was from the shame of being such a failure. She had to admit—it was true. She had doubted Kiyohime's guide.
Whether it was Rule One: "Follow him around," or Rule Two: "Beware the foxes," she had second-guessed everything. She thought stalking was wrong. She thought Kiyohime herself should be a subject of suspicion. And now… those doubts had doomed her! Even if the future version of her was still by Su Mo-nii's side, the fact that they hadn't progressed further made her feel terribly bitter. If only she had trusted Kiyohime's advice more… maybe the future would be different.
Head lowered, Sakura accepted Kiyohime's criticism with silent guilt, while Kiyohime took the chance to continue teaching her guide. She was determined to help her poor little Master become a winner in life. Just then, Illya tilted her head and looked curiously at the two who were whispering in the corner.
"Huh? Sakura-oneesan and Kiyohime-mama seem really close!"
As she spoke those words—
Pffft—!
Okita Souji spat out the tea she had just sipped, spraying it straight across the table and right onto Kiyohime.
"Ki—Kiyohime… Mama?!" she exclaimed, her expression a picture of chaos.
"W-What did you just say?!" Kiyohime's jaw dropped. Meanwhile, Sakura's face was one of utter disbelief, tinged with betrayal. She grabbed Kiyohime's wrist tightly—surprisingly strong for a six-year-old.
"Berserker… What's going on here?"
It was over. The unbreakable alliance had shattered. Their sisterly friendship… was no more. Faced with the title "Kiyohime Mama," Sakura could no longer stay calm. She stared at Kiyohime with the wounded gaze of someone who had just been betrayed by the person she trusted most. So that was it! So, this was the reason her future self failed! Everything Kiyohime said about not following the love guide properly—lies! Excuses! All of it was just a cover. She had taught Sakura her guide just to sneak ahead and snatch Su Mo-nii for herself! No wonder she was acting so nervous earlier!
So that "fox" she warned her about… It was Kiyohime all along! Sakura understood now. She had seen the truth. This world was cold and cruel. Even a six-year-old girl could be deceived. No… not could be—had been. She had been tricked. The world had always been cruel. Hadn't she almost been thrown into the worm pit before? Only after meeting Su Mo-nii did her fate begin to change. And it was under Su Mo-nii's protection that she became more innocent… and more trusting. That's why she had believed Berserker's lies.
"N-No! I didn't! I swear I didn't!" Kiyohime cried in panic.
"Master, please believe me!" She shook her head frantically, clearly flustered. She really hadn't meant to steal Sakura's beloved! She had shared her love guide sincerely! She hadn't had any other thoughts… not even a little bit!
…Well, maybe just a tiny bit.
After all, Su Mo-sama was incredibly handsome, kind, strong, and treated her with respect…
Ugh! No! She had to stop thinking like that! If she kept going, she really wouldn't be able to turn back! Wearing an utterly guilty expression, Kiyohime slumped her shoulders in defeat, looking like a child who'd just been caught red-handed.
Sakura, on the other hand, looked absolutely heartbroken, staring at her with eyes full of sorrow and betrayal. Just like that, the dynamic between the two flipped in an instant.