Sneaking inside was a piece of cake, since you we’re invisible and could just walk though objects. Matsuri was going through her mourning routine, currently sitting on her bed, brushing her long black hair. She was pretty focused on making sure her hair looked nice, so much so that you doubted she would have noticed even if you we’re visible. As always, you felt a pang of envy inside. You we’re an entire year older than she was. And even after adding those wonderful three inches, your sister was still a full head taller than you, not to mention further along in her figure. With her perky D’s, she was easily the most mature looking girl in her class, if not in her entire grade.
But it occurred to you that you really had no reason to feel inferior. Sure, she had an ample bust size. So what, you could reshape the entire world just by willing it. Once you factor in nigh-omnipotence, a younger sisters somewhat more developed physique became a trivial thing. In fact, just to be a good sport about it, you decided that you could give Matsuri a little push. She’s always enjoyed being the biggest, so it stands to reason that she would have no objections to growing even more.
You looked your sister over, wondering where to start. After pondering it for a moment, you decided to go with the bust. Concentrating, you imagined them swelling up, expanding upwards through the sizes. You made sure to go nice and slow, so that Matsuri wouldn’t take notice. You watched, seeing the straps of your sisters navy blue bra start to tighten, indenting faintly into the skin at first. Matsuri paused her hair brushing, looking slightly puzzled. She rolled her shoulders a bit, trying to get comfortable, ignorant to her expanding chest. “Urg, when did this thing get so tight” She said to herself, reaching back and popping the clasp, letting the bra pop off with a small, but pleasant amount of spring. Looking down at her chest, Matsuri blinked a few times, before cupping the underside of her breast, giving them a little bounce. “Looks like I grew a bit more. Oh man, I can’t believe I didn’t notice” Standing up, she posed in front of her mirror, holding her chest out proudly. “Hmmm…Looks like a DD, or maybe even an E. Nayuki is going to die when she see’s.” It was hard not to chuckle a bit at your sister. Won’t she be surprised when you tell her just where this little growth spurt came from.
Matsuri Finished admiring her new assets, and went back to getting ready to face the day. She started by digging through her underwear drawer, looking for a bra to fit her newly improved endowments. She managed to squeeze into a sports bra she founds, one with an extra elastic strap. What she didn’t notice however, was that while she had been searching, you’d been giving her another growth spurt, this time all over. As before, she didn’t seem to notice. Steadily creeping up past 5’9”, your sister was now more than a full head taller than you. She walked over to her closet, pulling out a T-shirt. When she tossed it on, she had to struggle to get her head through the hole, and even more so when she had to slide it past her chest. The material was stretched tight, the bottom of the shirt hovering just above her belly button. “Oh wow, guess I need some new clothing to. No surprise, for you at least, that she had to pull with all her might to squeeze into her shorts, since she was now breaching past 6 feet tall, an entire foot taller than you we’re.
As Matsuri headed over to check her appearance, she at last noticed something very ammis. Moment ago, her full length mirror had been just that, full length. As it was now, she was just a bit taller than it. Gazing at the mirror, and down at herself, she exclaimed “Oh my god, I’m huge”
You snicker a little to yourself, thinking that