Back at Naruto's old apartment building, Hinata, Hino and Tenata were currently speaking with a long purple-haired kunoichi wearing a cat mask and ANBU gear. Neko, as she was called, had been sent to speak with the girls and deliver a scroll with a jutsu array inside it. Apparently, the Hokage, who Hinata still believed was Tsunade while the other two knew better, had discovered a way to safely shrink their belly sizes and regain their fields of motion, at least temporarily.
According to Neko, Hokage-sama had developed a version that was guaranteed to work on the clones, but she wasn't sure it would work as well on the original. To this end, she had made up the scroll and ordered Neko to deliver and use the jutsu-scroll on Hinata, while Hino and Tenata watched with their Byakugans. This would allow the two to give feedback so Hokage-sama could perfect the jutsu for the Hinatas.
Hinata honestly wasn't so sure about doing this; even if the jutsu would only remain active for a few hours, she had come to love having her big, full belly. She felt only marginally better at knowing the jutsu was only meant to shrink its size rather then return her to her flat-bellied shape. She wanted to keep as much of it as she could, but when told it would make sex with Hino and Tenata much easier to accomplish and give them more options when in the bedroom, Hinata nearly snatched the scroll from Neko's hands. She hated herself for having grown so easily tempted by sex, but she just couldn't help it.
Before Neko could apply the jutsu (touching the formula to her belly), a knock came from the door. Surprised at having yet another visitor here and feeling curious about who it could be, Hinata slipped away to answer it. Upon opening the door and seeing who was on the other side, Hinata's jaw dropped in disbelief.
Before her stood someone who looked amazingly like her little sister Hanabi, only older and as well developed as Hinata herself now was.
She looked to be about the same age as Hinata, give-or-take a few months. Her long, dark-brown hair reached down to the middle of her back, with long parted bangs framing the sides of her face with a single lock of hair falling in front. To top off the amazing similarities, this young beauty possessed the same large lilac-tinted white eyes of her adorable little sister.
She was wearing a sleeveless, blue/purple v-neck shirt that only reached below her ribs, leaving her stomach completely bare, and seemed to be straining to hold back an amazing pair of D-cup breasts. What was once a pair of shin-length blue/purple pants could now barely pass as a pair of knee-length shorts with tears going up the outer sides to just under mid-thigh. This of course only served to show off more of the girl’s tantalizing skin than many would consider appropriate. She wore no sandals however, either choosing or being forced to go barefoot.
The girl fidgeted in place as Hinata continued to gape at her. The poor girl’s steadily reddening face and heavy breathing, which was progressively growing heavier and faster, was eventually enough to shake Hinata from her jaw-dropped silence. "H-Hanabi-chan!?! Is that you?"
The girl gave a small nod as she continued to fidget, though it wasn't from nervousness or feeling uncomfortable under Hinata's wide-eyed stare like the larger-bellied girl believed. "H-hai, Hinata-onee-sama. C-can, can I come in, p-please?"
Seeing the girl’s odd behavior increase, Hinata quickly ushered her 'no-longer-so-little' sister inside and started asking questions. "Hanabi-chan are you alright? How did this happen to you? Where did you find that backpack? And, hump?!?"
Hinata was shocked into silence as Hanabi interrupted her in the most unexpected of ways; by kissing her! Now as sisters, they had kissed plenty of times before, but nothing like this full-on lip-to-lip kiss that was currently taking place. Hinata's mind locked up, unable to process what was happening and leaving her completely at the mercy of her sister who had just tossed the backpack off to the side without a care. On feeling Hanabi's tongue brush against her lips, Hinata acted on instinct and opened her mouth to give Hanabi free access.
Hanabi, feeling encouraged by what she believed to be a positive reaction to the kiss, put a little more force into it, unintentionally forcing Hinata to step backwards where she quickly tripped and fell. Hanabi fell right on top of Hinata, smashing against Naruto, much to his displeasure. Hanabi paid his cramped wiggling no mind as she lay there on top of Hinata, staring down into the blushing, panting girl’s eyes, which showed a mix of confusion, shock, love and growing lust. "Well, this is quite a sight," said a familiar voice, causing the girls to tilt their heads up.
Seeing Hino and Tenata looking down at her with approving grins made Hinata give an audible gulp as she knew her girlfriends wouldn't be smiling like that unless they had some sort of plan. This was only further confirmed as she spotted Neko approaching with the scroll at the ready.
"Don't mind us, dears. We're just going to get this pesky scroll business out of the way. Then you two can continue," said Hino with this cheeky grin on her face showing that she was loving this.
Any protests Hinata may have had were shut down as Hanabi leaned down from on top of her belly and reclaimed her lips. The girl just would not be deterred no matter how much Hinata wiggled around under her. Her struggles quickly died off though, changing from muffled protests to muffled moans and muted screams of ecstasy as the jutsu was applied to her Naruto belly.
She could feel Naruto's discomfort as the womb around him shrank and squeezed him tighter then ever before. The compression of her uterus seemed to come in pulses and with those pulses came unimaginable pleasure. Soon enough, she was gripping any part of Hanabi that she could get a hold of and pulling her as close as possible, while kissing her sister back just as fiercely. With every pulse, her belly shrank and the closer Hanabi was pressed against her. Twice Hinata reached her peek as the jutsu did its work, twice Hinata lost ground in the ongoing tongue war, and twice she was forced to reclaim lost ground.
By the end of the jutsu, Naruto was nothing more than a slight bump in Hinata's belly, having shrunk even farther than Hinade. While Naruto wasn't hurt, he certainly wasn't comfortable either. Still, his nearly nonexistent movements (due to how cramped he was) left Hinata in a state of perpetual bliss and a desire for more.
Once Neko moved away, Hanabi immediately, if reluctantly and with a good bit of difficulty, got off of her sister. Before anyone could react Hanabi scooped the pleasure-drunk girl up into her arms bridal style and quickly made her way towards the bedroom where she planned to spend the next few hours with her sister.