The spring afternoon sunlight streamed through the tall windows of Tsumugi’s family estate. It was a peaceful evening — tea, cakes, and the easy chatter of five close friends who hadn’t gathered together like this since graduation.

Azusa sat primly on the edge of the sofa, attempting (and failing) to resist Yui’s clingy antics. “Azunyan, your hair’s gotten longer!” Yui said, reaching out to toy with one of her kouhai’s neatly tied pigtails.

Azusa groaned. “Yui-senpai, don’t mess it up! I just fixed it.”

“Oh, but it’s so cute! I missed it so much!” Yui cooed, wrapping her arms around Azusa and pulling her into a hug.

Across the room, Ritsu laughed loudly, balancing a teacup precariously on her knee. “Looks like Azusa hasn’t changed a bit! Still Azunyan, and still grumpy!”

Mio sighed, cradling her cup carefully. “You haven’t changed either, Ritsu. Be careful or you’ll spill that all over Tsumugi’s beautiful carpet.”

Tsumugi beamed, waving off Mio’s concerns. “It’s fine, Mio-chan. If anything happens, we’ll just clean it up.”

Before Mio could respond, the doorbell rang, echoing through the spacious room. Tsumugi perked up. “Oh! That must be the surprise Sawako-sensei mentioned!”

The girls exchanged curious glances as Tsumugi hurried to the door.

___

A moment later, their former teacher strode into the room, dressed as eccentrically as ever in a long, flowing cardigan paired with a studded belt. Behind her shuffled a much smaller figure.

“Good afternoon, girls!” Sawako chirped, gesturing dramatically to her guest. “I’d like you to meet a friend of mine—Dr. Keiko Hayami! She’s a brilliant inventor and physicist!”

The girls all blinked. Keiko, shorter than even Azusa, stood awkwardly near the doorway. Her long pigtails, paired with her oversized sweater and flats, made her look impossibly like a middle schooler.

Yui tilted her head, curiosity gleaming in her eyes. “Wow, she’s so small... Are you sure she’s not Azunyan’s little sister?”

Keiko froze, her eyes narrowing. “Little sister?”

Yui immediately waved her hands, laughing nervously. “Ah, I didn’t mean it in a bad way! I just thought—um, never mind!”

Azusa smacked Yui’s arm lightly. “Yui-senpai, don’t be rude!”

“I-I didn’t mean to be rude!” Yui stammered, clinging to Azusa as if for protection.

Keiko sighed, pinching the bridge of her nose. “Let’s just... move on.”

Sawako clapped her hands to break the tension. “Girls, I know this seems sudden, but Keiko’s here to offer you an incredible opportunity. Be nice and hear her out, okay?”

__

Keiko straightened up, brushing off her earlier frustration. “Thanks, Sawako,” she muttered before turning back to the group.

“I’ve developed a technology that can change how people’s size!” she began, her voice calm and professional. “Specifically, it can temporarily shrink living organisms to roughly one-twelfth their original size.”

The room went silent. Then, predictably, Ritsu broke into laughter.

“You’re kidding, right? Is this some kind of prank?”

“It’s not a prank!” Keiko yelped angrily, her face red, though her small stature made it hard to project the authority she wanted. “It’s real. I’ve spent years perfecting the device. It’s fully functional and perfectly safe.”

“Uh-huh,” Ritsu said, still snickering. “So like, turning people into dolls? So you could play with?”

Mio gave Ritsu a stern look. “Ritsu, don’t be rude.”

Keiko was glaring daggers at the girl, with her fists clenched at her sides.

Sawako clapped her hands sharply, drawing everyone’s attention. “Girls, enough! Keiko is a legitimate scientist. I’ve seen her work, and it’s incredible. You’d do well to listen to her.”

Tsumugi, ever the peacemaker, leaned forward with a smile. “I’m sure it’s very impressive, Dr. Hayami. Could you tell us more about how it works?”

Keiko relaxed slightly, before continuing as if nothing happened. “Thank you. And please, just call me Keiko.”

She glanced around the room. “Unfortunately, I couldn’t bring the machine here—it’s far too large. It’s actually installed on a private jet I’ve arranged for you. That’s where I’ll demonstrate its capabilities.”

Yui, who had been uncharacteristically quiet, suddenly perked up. “A private jet? Like the ones rich people have on TV?”

“Yes,” Keiko replied simply “It’s equipped with two cabins: one for shrinking and one for restoring your original size. Each cabin has a twenty-four-hour recharge time, so you can change sizes only once each day.”

Ritsu raised an eyebrow. “And what exactly do you want us to do?”

“Simple,” Keiko said, a sly smile forming on her lips, “I’m offering you an all-expenses-paid tour of Europe, where you’ll perform concerts in some of the most iconic cities in the world. With some… adjustments.”

“Adjustments?” Azusa asked warily.

Keiko stepped closer enthusiastically. “ It’s a publicity stunt for my invention, so… I need you to use it. Basically you’ll perform with one of you normal-sized while the rest are shrunken— I’m providing tiny instruments too. You just need to do is play music and adapt to your new size.”

The room fell silent again as the girls processed the idea.

Tsumugi was the first to speak. “That sounds... amazing! I’ve always wanted to tour Europe.”

“And I guess it’s not that crazy,” Ritsu admitted. “It’s just... weird.”

“Super weird,” Mio muttered, looking pale.

Azusa’s brow furrowed. “I’m not sure. Is it really safe?”

“Absolutely,” Keiko said. “And I can prove it when we get to the plane.”

Yui suddenly stood, raising her hand like a student in class. “I wanna do it! Tiny Azunyan sounds adorable!”

Azusa flushed. “Yui-senpai, don’t volunteer because of weird reasons!”

Keiko chuckled softly, her earlier irritation fading. “It’s nice to see someone excited about it. Alright, alright! Let’s get going!”

___

It was a half-hour ride in Sawako’s car before they reached their destination

“It’s so shiny!” Yui exclaimed, practically skipping toward the plane. “Azunyan, look! This is going to be our plane!”

Azusa trailed behind, lugging their shared luggage. “Yui-senpai, please focus! This is serious.”

“It’s a private plane, Azunyan!” Yui gushed. “Like the ones on TV! Do you think they’ll have cake inside?”

“This is incredible,” Tsumugi said, her smile as bright as ever. “Thank you, Keiko-san, for arranging this.”

Keiko, dwarfed even further by the towering jet, adjusted the oversized bag slung over her shoulder. “It belongs to my family… So let’s not smudge the windows before we even get inside, okay?”

Yui froze, her hand already halfway to the window. “Oops. Sorry, Keiko-chan!”

Keiko’s brow twitched. “Keiko-san.” She sighed. “Let’s just get inside. There’s a lot to go over.”

Ritsu whistled as they climbed aboard. “Man, if this is the kind of treatment we get, I think I can handle being turned into a doll for a while!”

“Don’t call it that!” Keiko snapped, flushing.

“Right, right. Miniature musician,” Ritsu teased, grinning.

___

The interior of the jet was just as extravagant as its exterior: plush seats, polished wood paneling, and even a small kitchen stocked with snacks. At the back of the plane, a heavy door marked Research Facility stood out, flanked by two smaller doors labeled Shrinking Cabin and Restoration Cabin.

“Azunyan, they do have cake!” Yui cried, already reaching for a plate.

Azusa pulled her back, scolding her. “Yui-senpai, we’re here for a meeting, not to snack!”

Keiko ignored the commotion, dropping her bag onto a table and gesturing for the group to gather. “If you’re done gawking, we need to go over the plan.”

Reluctantly, the girls settled into their seats, though Yui continued to sneak glances at the buffet. Keiko retrieved her tablet, its display lighting up with diagrams of what looked like a giant capsule.

“As I explained earlier,” Keiko continued impatiently, “the shrinking machine is installed at the back of the plane. It’s equipped with the latest advanced nanotechnology. When activated, it reduces the molecular spacing of everything inside the field, shrinking them to one-twelfth their original size.”

Mio looked uneasy. “You’re sure this is safe?”

Keiko exhaled sharply, looking up from her tablet. “Yes. You’ll be perfectly fine. I tested it. I even tested it on my dog once! It even gives increased durability for both living AND non-living objects!”

Azusa looked skeptical. “So… when it comes to living subjects, you only tested it once… on a dog…” Mio looked pale, trying not to faint at the spot from the implication.

Keiko coughed a few times, blushing in emberrassment “S-so, a-anyways, let’s get back to the topic.”

“Second cabin is what you’ll use to get back to normal. Each cabin requires a 24-hour recharge between uses. First four of you will shrink now, then we switch back and forth after each of your first concerts. To give you a little more time to prepare, the next concert will start in 2 days. You’ll need to stay shrunken to prepare for it while one of you remains normal-sized to assist and coordinate.”

“Wait, so one of us stays big while the rest are tiny?” Yui asked, leaning forward eagerly.

“Exactly,” Keiko said. “The normal-sized person will handle things like setting up your instruments, carrying you if needed, and interacting with the audience. Most things would be inconvenient if you all were small at the same time.”

Yui beamed. “That sounds fun!”

“Fun?” Mio repeated, still pale from the knowledge she’s the second test subject.

Ritsu slapped her hand on the table, grinning. “I call staying big for the first concert! As the leader, I gotta set the example!”

“Example? You?” Mio muttered, glaring at her.

“Me!” Ritsu shot back. “Hey, what’s with that glare? I’m very reliable when I want to be.”

Tsumugi raised a calming hand. “Let’s not argue. It makes sense for Ritsu-chan to stay normal for the first concert, so she can help set the tone for how we’ll manage things.”

Mio wanted to go first because she feared the small mad scientist, but when she thought about it, it would directly put Ritsu at risk instead. “F-Fine” She hesitated, her cheeks reddening. “I’ll choose to stay normal-sized for the last concert then. It’s in London, after all and only feels right.”

Azusa nodded thoughtfully. “That’s fair. Can we decide on who goes second later? I’m… not exactly sure how this whole shrinking thing will go…”

___

Keiko clapped her hands together. Despite her petite state, it was clear she’s used to bossing others around. “All right, then. If we’re done deciding who stays normal for now, let’s move on to the fun part.”

Mio gulped audibly. “The… fun part?”

Keiko smirked and gestured toward the Shrinking Cabin at the back of the jet. “Step right this way, ladies. It’s time to shrink.”

___

The group trailed behind her to the back of the jet, where a thick metallic door labeled Shrinking Cabin stood. Keiko pressed a button, and the door slid open with a soft hiss, revealing a clean, metallic interior. The floor gleamed under the soft glow of the overhead lights, reflecting their nervous faces.

“Whoa,” Ritsu muttered. “This looks like something out of a sci-fi movie.”

“It’s spotless,” Tsumugi remarked, stepping closer.

Keiko turned, narrowing her eyes at them. “Of course it is. And it’ll stay that way. Shoes off, all of you. I’m not letting you track dirt into my machine.”

Azusa hesitated. “Our shoes?”

Keiko crossed her arms. “Yes, your shoes. It’s standard protocol for a sterile environment.” She tapped her own flats against the floor, slipping them off to reveal her bare feet. Her toes wriggled slightly as if to make her point. “The plane is clean too, so there won’t be an issue. Normal girl should walk barefoot as well, that way, if you step on someone you’ll feel it.”

“Step!!??” Mio jumped in fright, hiding behind Ritsu

Keiko gave a dramatic sigh, rolling her eyes at Mio's reaction. “Relax. I won't be the one stomping on anyone. But....” She smirked. “I wouldn’t be sure about your friends. In any case it’s just a precaution to ensure no one gets accidentally hurt. Even if you do get stepped on, you should be durable enough to handle it.”

Mio’s expression remained horrified, her grip tightening on Ritsu’s shoulder.

Ritsu, meanwhile, couldn’t hold back her laughter. “Man, Mio, you’re jumpier than usual. Don’t worry—I promise to step very carefully when I’m big.”

“Ritsu!” Mio hissed, swatting her arm.

Keiko clapped her hands again to regain their attention. “All right, shoes off. Let’s move it. The longer you take, the less time you’ll have to practice at your new size.”

With varying levels of reluctance, the girls removed their shoes, placing them in a neat row beside the door. After a few minutes of hesitation and trying to calm Mio down, everyone stepped inside, settling cross-legged on the smooth, metallic floor.

“Ready?” Keiko asked, peering through the doorway.

“Not really,” Mio muttered, but Tsumugi nodded cheerfully.

Keiko rolled her eyes, muttering something under her breath as she flipped several switches. “Initiating shrink process. Don’t move around too much, or you might lose your balance during the transition.”

Azusa blinked. “Lose our balance?”

“Don’t worry about it,” Keiko replied in a hurry, not hiding her anticipation at all. Not waiting any longer, she pressed a button, closing the door and filling the cabin with a warm blue light.

Ritsu, standing by Keiko, couldn’t help but notice a gleaming smile on her face. “You’re really enjoying this, huh, Keiko-chan?”

Keiko shot her a glare, becoming serious again. “It’s Keiko-san. And yes, I am. Now be quiet and watch.” She typed something on the control panel, then pulled a switch and pressed the final button, making the machine hum intensively.

Inside, the girls looked around nervously as the blue light intensified, enveloping them in a warm glow. A low hum filled the chamber, growing louder and louder until—

Pop!

In an instant, the light dimmed, and the door hissed open again.

Ritsu peered inside, her jaw dropping. “Whoa.”

There were four tiny versions of her friends. Each one was no more than a few inches tall, their clothes and accessories perfectly scaled down.

Yui wobbled slightly as she stood, looking around in awe. “Azunyan! You’re so small!” she exclaimed, rushing over to hug her fellow guitarist.

Azusa groaned, squirming in Yui’s grasp. “Yui-senpai, you’re small too! And don’t squeeze me so hard!”

“Perfect,” Keiko said, stepping into the cabin. She bent down to get a better look at the four tiny figures now sitting on the floor, their faces filled with varying levels of awe and apprehension.

“Huuuge!” Yui exclaimed, staring up at Keiko, who now loomed over them like a giant. “Azunyan, look at how big she is!”

Azusa groaned. “Yui-senpai, you’re the one who shrunk. Everything else stayed the same.”

Tsumugi giggled, spinning in place to admire her new tiny form. “This is incredible! Keiko-san, you’re amazing!”

Mio, meanwhile, was frozen in place, staring up at the towering figures of Ritsu and Keiko with wide eyes. “This… this is so weird…”

Ritsu snickered, crouching down to get a better look at her tiny bandmates. “You guys look like action figures! I can’t wait to mess with you—”

Keiko stepped forward, a devilish glint in her eye. “Hold that thought, Ritsu. I have unfinished business to attend to.”

She crouched down, the tiny figures barely noticeable next to the giant scientist. “So, Yui,” Keiko said, her voice dripping with mock sweetness, “who’s the little sister now?”

Yui tilted her head, confused. “Huh?”

Keiko didn’t wait for an answer. She extended her foot, her toes wiggling playfully before pressing lightly against Yui’s side. The tiny guitarist squeaked, tumbling over onto the floor.

“Wha—Keiko-san!” Yui squirmed, trying to push the enormous toes away as they pinned her down. “What are you doing?”

“Now, you will apologize for your disrespect!” Keiko said, trying to muster an intimidating laugh but ending up sounding more mischievous than villainous. “Mwahaha! Bow before me, the mighty Keiko-sama!”

Yui blinked at the enormous toes toying with her, then giggled. “Keiko-chan, your feet are so soft!”

Keiko’s cheeks turned bright red, and she quickly pulled her foot back. “O-Of course they are! I take good care of them!”

Azusa smacked her forehead. “Yui-senpai, why would you say that?”

Yui looked up innocently. “But it’s true!”

Keiko, still blushing furiously, pointed her foot toward Yui again. “If you’re so impressed, then kiss them! That might earn you my forgiveness.”

Ritsu burst out laughing, nearly doubling over. “You’re really getting into this, huh, Keiko-chan?”

“Keiko-san!” Keiko snapped, her foot twitching slightly. “And I’m perfectly serious.”

Yui tilted her head thoughtfully, then leaned forward and pressed a light kiss to Keiko’s big toe. “There! Happy?”

Keiko froze, her face now an impossible shade of red. “I… uh… yes! Good! That’s… acceptable!” She quickly withdrew her foot and stood up, brushing imaginary dust off her skirt to regain her composure.

Ritsu, watching from the doorway, burst out laughing. “Keiko-san, you’re way scarier than I thought you’d be!”

Keiko shot her a glare, her cheeks still flushed. “I’m just making sure everyone understands their place.”

Mio, watching the entire scene from the edge of the cabin, groaned. “I already regret this.”