Kasumi stayed silent for a moment, her usual persona broken by such a bizarre turn of events. Her shaking hands crept forward, so tempted to see if the shrunken girl before her was real.
"Mia-chan... you're..."
Mia's eyes grew wide as the colossal shadow of the petite school idol loomed over her. "I'm what?"
"You're sooooo cute!! Look at you, Mia-chan! You really are just a cute little dollie for Kasumin now~!" Faster than she could react, Mia was grabbed out of the pile of her discarded clothes and held up naked in front of Kasumi's prying eyes.
"Kasumi-chan, s-stop, holy shit stop! I'm tiny now, and you're huge!! Put me down now!!" Mia couldn't decide whether to cover her privates or try to escape Kasumi's fingers, so in a panic, she successfully did neither.
Kasumi examined Mia's tiny, naked body, looking at all the finer details of her shrunken senpai.
"You really are just the perfect size now, I think I like you this way more... Gosh and look at those curves! You're younger than me but you have a body like that! Are all American girls like you? Kasumin is so curious now!"
Mia shrieked in fear and frustration as giant fingers began feeling up every millimeter of her body. Kasumi saw no wrong in touching Mia's most sensitive areas. She started by squeezing Mia's well-developed boobies between her finger and thumb, causing Mia to let out the most erotic moan Kasumi had ever heard. This only encouraged her more as Kasumi used her fingernail to tickle Mia's tummy and exposed armpits. The tiny foreigner's limbs flail wildly as Kasumi has her way.
"S-stop! Stop! D-don't touch me anymore! Get help, someone help me!" Mia cried out through her strained laughter. Tears streamed down her face as Kasumi's tickling continued, soon moving on to between Mia's thighs and bare feet.
"Oh this is just too amazing... Kasumin isn't even mad that you ate my special chocolate, this totally makes up for it!"
"It was the chocolate that did this!?" Mia shouted, finally getting a chance to breathe.
"Kasumin doesn't know, it's just a guess! But things turned out okay I think. You're gonna love being my little dollie, Kasumin promises~" Chills ran down Mia's spine as Kasumi gave her a devilish grin.
The school idol's playtime continued as she realized Mia's nipples had become hard from all the intimate touching. Kasumi cooed seeing how easily she could control her tiny friend now. Mia could be a little cold and standoffish, not to mention arrogant. "But now look at her, melting in my hand with just a touch from my fingertips..."
Kasumi lightly pressed the pad of her finger onto Mia's hard nipples, feeling the full squish of her tits in one small press. Mia once again moaned, but this time it felt like she was really trying to fight back. Kasumi found this somehow even more cute. Moving her fingers between Mia's thighs, she could she some wetness developing between Mia's cleanly shaved legs.
"Mia-chan, you're so naughty, getting off to something like this. How unbecoming of a school idol..." Kasumi whispered seductively while licking her lips. The temptation to go all in and insert a finger into Mia's vagina was there, but Mia was so small that a finger might be too big. Kasumi would have to be satisfied with rubbing her outer vulva. Mia bit down hard on her lip and mumbled various swears each time Kasumi brought her closer to cumming. The platinum-haired girl's juices dripped down Kasumi's finger the more she was massaged.
For Mia, she had only just turned 14, and she hadn't learned what masturbation was or how it worked until relatively recently. And yet here was Kasumi, getting her off without breaking a sweat.
But just as things were reaching their climax, Kasumi heard the school bell ring. Lunch was over, and the second half of the day's classes were about to begin.
"Darn, Kasumi was just about to get to the good part... Oh well, we can play more after class, Mia-chan~" Kasumi said as began to gather up her things. She licked the finger covered in Mia's vaginal fluids and gave a sweet, innocent smile.
The brief moment of reprieve from Kasumi's unwarranted molesting of her gave Mia a chance to properly think and breathe. "S-shit! Let me go, put me down and go get help! Call a teacher, Emma, Rina, anyone!! You can't do th--mmpph!" Mia's mouth was covered by Kasumi's index finger, muffling her tiny please with ease.
"Shh, Kasumin has to get back to class now, so we'll talk later. And maaaaybe help you figure out a way to grow back, Kasumin isn't sure yet."
With those indecisive words, Kasumi looked around the clubroom. She enclosed her fingers around Mia, trapping her in a sweaty fist. She put her special chocolate away in her bag and looked down at the hand containing her shrunken senpai.
Where should Mia go while Kasumi's in class?