The already tall and impressive Kyoko was jealous of the once small Nayuki, Nayuki smiled to herself, she loved that she was now bigger, but... she couldn't just leave her friend hanging like this. Smiling as she looked at Kyoko who was still looking at the fall, Nayuki worked her magic.
Kyoko felt a strange warmth fill her body, it started around her chest area and grow outwards, expanding all over her body, she looked at herself wondering, blushing slightly as the warmth felt oddly nice.
Distracted by the warmth she hadn't noticed that she'd begun to grow, it wasn't in till her top, begun to push tighter than normal around her breasts, hugging them to the point where she snapped out of her trance like state. She blushed as it felt quite good, about to open her mouth to mention something to Nayuki, she was cut off by the same feeling in her shorts, and shoes, and all her clothing in fact as she slowly begun to inch upwards.
Nayuki watched and giggled slightly speeding up the growth as Kyoko gasped, stumbling backwards as her once large breasts jumped to the huge section as they reached the J cup sizes in a matter of seconds, her top unable to withstand the sudden attack from her breast flesh ripped to shreds, her bra struggling, fighting a losing battle as her much larger than normal nipples, puffed up slightly.
Before a thought about how to cover herself crossed her mind, Nayuki giggled and gave her another boost, wanting to see how big she could make something, Kyoko rocketed upwards, gaining feet in seconds before Nayuki giggled, realizing that she should stop her growth as Kyoko's head was already pushing ageist the ceiling while sitting.
Kyoko, blinking, blushing, confused, sitting in the remains of her clothes and if she where to stand, Nayuki would guess that she would be around 15 feet tall, gave or take a foot or two, she couldn't give a good guess due to the that that Kyoko was sitting.
"W-What just happened" Kyoko asked, nervously and shyly, shaking slightly panicked at her sudden growth spurt. Nayuki soon realize she had to make a choice...