Kira Daidouji had tricked-- I mean, convinced the Kasuga sisters to take part of an experiment she has been working on. Her newest creation is what she is calling "Variable Ether Matter" (name pending). It is special substance similar to her ether-controlled slime she uses, but has a special property where it can supposedly change the state of matter it has depending on the celestial power applied to it. Kira believes that with the four sisters, she can test the effects of it better than if she were to get anyone else to do so. Maori was hesitant, knowing what kind of person Kira was, but the twins insisted they wanted to help, so the other two sisters followed suit. The four followed Kira into her rather small laboratory where she says she wants to run the experiments in. As the four sisters try to look around, Kira pushes a button and suddenly tubes drop out of the ceiling and stuck into the sisters' mouths. As it turns out, Kira's way of experimenting on her newest creation was to stuff the sisters full of the matter and see how it reacts! This is what she would observe happening with them.

First are the twins Koito and Kouta, both of whom celestial energy seem to cause the substance to turn into gas, causing their bodies to turn spherical, making them start floating in the air. Not only that, but the gases forming inside the two started to especially build up within their feet and hands, causing them to swell up significantly. They became quite the big blimps.

Second is Tsuzune, who's celestial energy started making the substance more dense. Not necessarily turn it into a pure solid, but still solid enough where her body started to balloon out like she was stuffed full of food. In particular, a lot of the mass started to build up on her butt, causing it to grow really big to the point that it started to look like her rotund body was sitting on a giant beanbag.

Third and finally was the family matriarch Maori, who's celestial energy surprisingly enough started to make the substance liquefy, making her get filled out like a water balloon. Except it didn't seem to really be water, as Maori's skin started to turn blue, like she was slowly turning into a blueberry. Not only that, but a lot of the "juice" started to gather inside her breasts, making her already large breasts even larger to the point that they were almost as big as she was, much to Kira's annoyance.

Regardless of the oddities and Kira's personal opinions, her experiment seems to be going really well. Maybe even TOO well. Kira didn't really think that the substance would expand it's volume that much, meaning that at best the Kasuga sisters' bodies would bloat up to make them just little bit chunky. But instead, their bodies grew much bigger than what she was anticipating, which is bad because Kira's laboratory was rather small. As their bodies started to push Kira's equipment aside, she started to get angry at them as her experiment started to get out of hand. But with her being annoyed by having no room to move around, Koito and Kouta suddenly tag teamed on Kira by squeezing Kira in the middle of their round bodies, demanding Kira to return them to normal. Tsuzune also joined in, threatening to squash Kira beneath her fatty body if she doesn't comply. Kira was really adamant that she didn't own her anything before she saw a large boulder drop in front of her. While Maori was not able to move due to her berryfied body, she still can channel the powers of Ohtsuchi. Realizing that Maori would wreck her lab if she wanted to, Kira gave in and promised to turn the four sisters back, as much as she doesn't want to. But will Kira be able to revert what she has done? For her own safety, she hopes so.

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A story-illustration collab with  toyorai involving the four Kasuga sisters getting bloated up into balloons in various ways by Kira. Illustration by me. Story by them with changes by me.