A Certain Magical Index: The Primal Spirit Descends to My Side

On a late July morning, the sunlight, still somewhat gentle, streamed in through the cafeteria's floor-to-ceiling windows, spreading a warm, golden dapple across the floor.

In the cafeteria of Tokiwadai Middle School, many students were already having breakfast. The soft clinking of cutlery and the hushed laughter created a comfortable atmosphere.

Shirai Kuroko sat by the window, a refined Western breakfast laid out before her. Perfectly toasted bread was served with fried eggs and rows of pan-fried cherry tomatoes, while a cup of black tea steamed gently.

Although it's the middle of summer, it would be cooler to wear just a white shirt, but Tokiwadai's school rules require students to wear this uniform at all times, which is really strange.

Her gaze wasn't on the breakfast, but rather fixed on the sky outside the window. The sunlight was already quite dazzling, streaming through the glass curtain wall and illuminating the few broken tea leaves at the bottom of her teacup.

"Big sister, the UV index is really high today." Shirai Kuroko picked up her teacup, blew on it gently, and spoke in a tone as if discussing some important scientific topic, "According to the weather forecast, the UV intensity in late July has reached a level where protective measures are necessary. If you don't take precautions against the sun, it can not only cause sunburn and accelerate aging, but may even increase the risk of skin cancer..."

"What are you talking about so early in the morning..." Misaka Mikoto sat opposite, spreading butter on toast, leaning back casually in her chair. "It's just sunbathing, what's the big deal?"

"Sunbathing and sunburn are fundamentally different." Shirai Kuroko put down her teacup, pulled a tube of white-packaged sunscreen from the pocket of her pleated skirt with a movement as smooth as magic. "So, Onee-sama, please let Kuroko apply the sunscreen for you!"

"I can apply it myself." Misaka Mikoto's brow twitched, her tone clearly wary.

"But my older sister clearly didn't apply it."

How do you know I didn't put it on?

"Because if my sister applied sunscreen, the difference in skin radiance should be at least one or two levels, and the visibility of pores would also be significantly different from when she didn't apply sunscreen..." Shirai Kuroko's eyes sparkled. "Especially since my sister didn't wear lipstick today, and her lip color is a natural pink, which further confirms my judgment."

"What do you usually observe?!"

"Observing my older sister is Kuroko's daily routine as her junior and roommate."

Misaka Mikoto took a big bite of her toast, as if trying to chew up and swallow all her frustration. "No thanks, it's too much trouble..."

"That's wishful thinking!" Shirai Kuroko retorted without backing down, even leaning forward half a chair. "Even if you don't get a tan, the damage from UV rays to the skin is cumulative! Damage accumulated in your teens will all come out in your twenties, and then...!"

"Stop, stop, stop!" Misaka Mikoto raised one hand and held her forehead with the other. "I know, I know, I'll apply repair lotion after sunbathing, is that alright?"

"Prevention is better than cure; that's basic medical common sense." Shirai Kuroko shook her head, her expression shifting from persuasion to determined seriousness. "So, Kuroko will now help Onee-sama with her sunscreen routine!"

She stood up, twisting open the cap of the sunscreen as she approached Misaka Mikoto.

"Start with the cheeks, then the neck, collarbone, arms... Of course, it would be best to apply it all over the body..."

"Stay away from me!"

Misaka Mikoto instinctively stepped back, the chair leg scraping against the floor with a harsh screech. She held her hand between herself and Shirai Kuroko, a faint blush rising on her cheeks.

"I'll apply it myself! I'll apply it myself!"

"Will you really apply it properly, big sister? You won't just smear it on your arm and call it a day, will you?"

"I'll apply it carefully!"

"That's perfect!" Shirai Kuroko's eyes suddenly lit up. "Kuroko, I have high-SPF waterproof and sweatproof sunscreen here, and it even has whitening and moisturizing effects..."

"I know you carry this with you at all times!"

"Because ultraviolet rays are the biggest enemy of the skin." Shirai Kuroko puffed out her chest matter-of-factly.

Just as the two were about to enter the next round of their conversation, a cheerful voice came from the direction of the cafeteria entrance, which prompted Misaka Mikoto to quickly push Shirai Kuroko away and sit down herself.

"Good morning, Shirai-san, Misaka-senpai!"

The two girls turned their heads simultaneously and saw two girls in identical summer uniforms walking towards them. Leading the way was Wannai Kinuho, with smooth chestnut-brown short hair styled in an inward-curling bob, the ends swaying gently with her steps, a gentle smile on her face. Beside her was Awafuki Manbin, also with long black hair, gentle and composed, walking quietly beside her companion, giving them a slight nod.

"Wanai-kun, Awafuki-kun." Shirai Kuroko quickly adjusted her posture, discreetly tucking the sunscreen into a hidden pocket of her skirt, regaining her dignified and elegant demeanor. "Good morning. You're here very early today."

"We just finished breakfast and were heading back to the dorm." As Wanai Kinuho approached, her gaze swept back and forth between Misaka Mikoto and Shirai Kuroko, and she smiled slightly. "I saw Shirai-san and Misaka-senpai talking about sunscreen over there... Did I disturb you?"

"Not at all..." Shirai Kuroko replied without changing her expression. "I was just giving my sister a lesson on sun protection. Are you two interested in UV protection? I have some extra..."

"No, no need! Thank you!" Wannai Kinuya quickly waved her hand.

At this moment, Pao Fuwanbin calmly spoke up, steer the conversation in a completely different direction: "Actually, we came here to invite the two of you to participate in an event."

"An event?" Misaka Mikoto tilted her head.

"Yes. There's a swimsuit model photoshoot at the 'Seaside Plaza' in the Second School District this afternoon," Kinuho Wanouchi chimed in, clasping her hands together, her tone carrying a hint of anticipation and invitation. "It's a summer new product launch jointly organized by several clothing brands in Academy City. They need some student models to showcase this year's new swimsuits... We received an invitation and can bring a friend along."

"Swimsuit...model?" Misaka Mikoto's voice paused involuntarily.

"Yes!" Kinuho Wanai added, as if sensing her hesitation, "Both Awafuki and I think this is a pretty rare opportunity..."

"And I heard that this year's swimsuit styles are especially cute," Pao Fuwanbin added softly.

The moment Shirai Kuroko heard the word "swimsuit," her brain went into overdrive. Swimsuit! Her older sister's...swimsuit? Her older sister in a swimsuit! Sunshine, beach, or even indoor lighting. But it doesn't matter! The important thing is that her older sister will be wearing a swimsuit!

As the most loyal junior and roommate, I naturally have the obligation and the right to watch and protect my older sister's swimsuit pose up close!

"This...this is a really great opportunity!" Shirai Kuroko turned around almost instantly, her tone switching from that of a sunscreen instructor to that of an enthusiastic event planner. "Onee-sama! It's so kind of Wannai-kun and Awafuki-kun to invite us like this, we should definitely accept!"

"Wait, Kuroko, weren't you just saying that UV rays are the biggest enemy of the skin?"

"But since it's an indoor swimsuit show, there's no need to worry about UV rays!" Shirai Kuroko's answer flowed as if it had been rehearsed beforehand. "Besides, since it's swimsuits for a brand launch, the fabric and cut must be carefully designed for comfort; they'll definitely fit you perfectly, Onee-sama!"

Misaka Mikoto looked at the junior in front of her, whose eyes seemed to be burning with fire, and couldn't help but twitch her lips. "I said... you want to see me in a swimsuit, right?"

"That's certainly one reason!" Shirai Kuroko admitted without hesitation, her tone shockingly confident. "But it's also a valuable opportunity to strengthen friendships, enrich campus life, and expand our social circles! Wannai and Awafuki specially invited us; wouldn't it be impolite to refuse?"

After Shirai Kuroko finished speaking, she winked at Wanai Kinuho and Awafuki Manbin, who were standing to the side. The two were stunned for a moment, but then immediately understood.

"Yeah, Misaka-senpai!" Kinuho Wanai joined in the persuasion, "It wouldn't hurt to just go and take a look!"

Pao Fuwanbin nodded gently, his gaze warm as he added the last sentence: "And... I heard there are many different styles of swimwear to choose from at this year's exhibition..."

"..."

Misaka Mikoto fell into a brief silence, her gaze sweeping back and forth across the three faces before her. Shirai Kuroko's eyes were filled with pleading and expectation, Wanai Kinuho smiled gently awaiting her answer, while Awafuki Manahira stood quietly to the side, his expression gentle, as if he would understand whatever choice Mikoto made.

"Seriously..." Misaka Mikoto sighed, picked up the coconut soda on the table and took a sip. "Okay, okay, I'll go. Anyway, I don't have anything to do this afternoon."

Shirai Kuroko's eyes lit up instantly, and she clasped her hands together at her chest as if she were about to ascend to heaven.

"However..." Misaka Mikoto put down her teacup and looked up at the three people in front of her. "I'll have to choose my own swimsuit..."

"How could that be!" Shirai Kuroko exclaimed righteously. "How could Kuroko do such a thing! Just seeing my sister in her swimsuit... no, just spending a pleasant afternoon with my sister is enough for me!"

Misaka Mikoto looked at her "I almost blurted out the truth" expression and sighed again, but the corners of her mouth curled up almost imperceptibly.

"Then it's settled." Kikunojo clapped her hands, a relieved smile on her face. "The meeting time is 1 PM, at the east entrance of the second school district. See you then?"

"Okay, I understand." Misaka Mikoto nodded.

Shirai Kuroko radiated an indescribable joy, her mind already planning a hundred different compositions for photographing her older sister in her swimsuit.

"Oh, right, Shirai-san," Wanai Kinuho added as if remembering something before turning to leave, "sunscreen will also be provided at the event."

"I know," Shirai Kuroko replied without changing her expression, only to be tapped on the back of the head by Misaka Mikoto. She then spoke again, "I understand... Thank you very much..."

After breakfast, Shirai Kuroko and Misaka Mikoto walked out of the cafeteria side by side. The sunlight had completely bathed the stone paths of Tokiwadai Middle School. Under the shade of the trees, students hurried by in twos and threes, carrying their textbooks. In the distance, the fountain shimmered with tiny sparkles in the sunlight.

Shirai Kuroko walked briskly, clearly in a good mood; even her gait had a cheerful rhythm. The scene from just moments ago was replaying in her mind.

My older sister agreed to participate in the swimsuit event; it's like a gift from fate!

"Onee-sama! Since we've decided to go, why don't we invite a few more people along?" Shirai Kuroko suddenly slowed her pace, turned to look at Misaka Mikoto, a calculating glint in her eyes. "The more people, the more lively the atmosphere will be!"

"Who are you calling?" Misaka Mikoto asked casually, looking down at her phone and scrolling through messages.

"Hatsuharu-san and Saten-san!" Shirai Kuroko answered matter-of-factly, clasping her hands together in front of her chest. "And Kofun-senpai... even though she always has a stern face, she should participate in these kinds of activities occasionally to relax."

Misaka Mikoto thought for a moment and nodded: "That's true. Haru and Saten would probably like this kind of activity... Let's go, it's on the way anyway."

When the 177th branch of the Discipline Inspection Commission opened that familiar door, the room was bustling with activity.

Shiori Haru sat in front of the computer, her fingers flying across the keyboard, the screen displaying rows of densely packed data streams. Ruiko Saten sat in the chair beside her, munching on a bag of potato chips, flipping through a fashion magazine in one hand, a tablet on her lap browsing an urban legend website.

Hearing the door open, she looked up, a potato chip still in her mouth, and mumbled a greeting, "Ah, Misaka-senpai, Shirai-kun!"

"You're here?" Shiori Uiharu peeked out from behind the computer screen, blinking. "What brings you here today?"

Shirai Kuroko strode into the branch office, came up behind Uiharu Kazari, and massaged her shoulders a few times before saying, "Uiharu-san, Saten-san, there's a swimsuit fashion show this afternoon, co-organized by various clothing brands from Academy City. My sister and I have decided to attend, and we'd like to invite you to join us."

"A swimsuit fashion show?!" Saten Ruiko sat bolt upright, forgetting even her potato chips. "Really?! Where? When?"

"At 1 p.m., at the seaside plaza in the second school district. Wan Nei and Pao Fu invited us, saying we could bring our friends along."

"Wow—! This is amazing!" Saten Ruiko jumped up, her eyes shining. "Swimsuits! New arrivals! A fashion show! This is the event of my dreams!"

Uiharu Shiori stopped what she was doing, her eyes sparkling with curiosity, but looking at her hands, she murmured, "Ah... do I have to go too?"

"That's right, that's right!" Saten Ruiko excitedly pulled up Hatsuharu Kazari and spun her around.

Seeing the two of them so excited, Shirai Kuroko nodded, then turned her gaze toward another desk in the branch office.

Behind that table, Kofumi was holding a cup of coffee, intently flipping through the documents in her hands.

She was wearing the shirt issued by the disciplinary committee, with her own coat over it, the overcoat draped over her shoulders swaying with the air conditioner behind her. Hearing their conversation, Kofumi merely raised her eyelids and glanced at them indifferently, then continued looking down at her documents, as if she hadn't heard a thing.

"Koufu-senpai!" Shirai Kuroko turned and walked towards her. "You should come along too!"

Kofumi put down her coffee cup, looked up, and her expression was conflicted. She wanted to go check on things, but she still had some work to do, making it difficult to decide. "I still have work..."

"Work is never-ending!" Saten Ruiko rushed over, placing her hands on Kofune Miu's desk, her eyes sparkling. "Kofune-senpai works every day, she should take a break sometimes!"

"And maybe we can even take some footage from this swimsuit event to use as a reference for the Disciplinary Committee's publicity work," Haruharu Kazari chimed in, her tone carrying a hint of serious consideration. "For example, to learn about the security procedures and venue setup for large-scale events in Academy City..."

"Exactly!" Saten Ruiko nodded quickly. "We're doing this for work and study!"

Looking into the three pairs of expectant eyes before her, Kofumi Miwa remained silent for a moment, then picked up her coffee and took another sip. "Okay... fine... but I haven't bought a swimsuit in ages..."

"It's alright!" Shirai Kuroko immediately chimed in, cutting off Kofumi Miwa's words. "The company will provide them; you can choose whichever you like."

"Besides, Kofuku-senpai is so pretty, she would definitely look great in a swimsuit!" Saten Ruiko blurted out.

Kofumi's eyebrows twitched, and she stared at Saten Ruiko expressionlessly for two seconds. Saten Ruiko felt a little guilty under her gaze, shrank her neck, and quietly took a half step back.

After a brief silence, Kofumi sighed. "I understand..."

Shirai Kuroko, hands on her hips, nodded with satisfaction: "It's settled then! We'll meet at 1 PM at the east entrance of the Second School District's Seaside Plaza! Don't be late!"