Aside from being illegal, tattooing a prepubescent is actually a fairly stupid idea if you want the design to remain clear and in the same place, because your skin stretches and grows as you age and does both of those things a LOT during puberty. Since we never actually see Mion's tattoo, we don't know how realistic to that it is, but since it is supposed to be a demon's head/face, possibly surrounded by flames of some kind, I'm sure an experienced tattoo artist could have administered the design in such a way that any warping looks intentional for added scary effect.

June 25th, 2021

In all the times that they had switched, Shion had never imagined what would happen if they got caught.

Silly of her, perhaps. Maybe it was because Mom and Dad and even their demon-eyed grandmother never seemed to be able to tell even the slightest difference between them, that no one, absolutely no one, in their whole entire family was capable of knowing whether it was actually Mion or Shion who pranced towards them in Mion's clothes, wanting this or that thing.

Maybe it was because their family never actually knew they switched, and was never ready for it. The first time, Mion had told her very carefully what she'd been doing and saying before she'd come out to check on her sister, and then Shion had pinned her hair up and gone back to the kitchen where they were making treats, and acted just like Mion, remembered all the things Mion had been doing, and picked up exactly where she had left off. Their parents, their family, nobody ever suspected because nobody ever thought it was possible. After all, to switch, the twins needed to be in accord, and why would obedient Mion, or isolated Shion, ever think of upsetting their family in such a way?

But now, surrounded by gloomy and hard-faced adults, a chill ran down Shion's spine, and suddenly, she thought that she might've asked for one treat too many. Was a feast really worth –whatever this was? Why were they all looking at her so intently? Did they know? Had she somehow slipped up in pretending to be Mion?

Shion had to gather every ounce of calm, every bit of the legendary aura that the Sonozaki family leader was supposed to exude, to keep herself from shaking like a leaf. She'd heard, once, that if twin heirs were born in their family, the youngest was supposed to be strangled before they got their first cleaning, before they were even properly welcomed into the world. She hadn't been killed, but –wasn't she the disposable twin, after all? If she and Mion were going to be punished, Shion knew she would get the lion's share of it.

"Mion." her grandmother's voice came, sharp and cracking like a whip, and Shion stood straight upright, her shoulders quivering as she stared ahead in the most formal way she knew how. "It's time."

"Yes, Batcha." she said, proud that her voice didn't quiver. This was okay, right? Their grandmother had called her by Mion's name, so she wasn't in trouble, was she? This was just another of those things, those formal meetings or ceremonies or whatever that honored their family, and Oyashiro-sama, and their place in the village. That was why most of her relatives were here, minus Mom and Mion at the amusement park. They were here to look at the heir.

Time for what, though? Shion wondered nervously as her grandmother started in on a very long and dry speech about Hinamizawa and Onigafuchi and the Sonozaki Family, inheritors of the demon, and Mion's place in that legacy. Mion hadn't mentioned any special meetings or upcoming events, and if she knew one would happen today, she wouldn't have let Shion switch with her. With official business, they only switched for meetings on the village council or stuff like that, boring stuff that didn't really matter and that Mion didn't really need to be there for.

This wasn't like that.

Not at all.

Shion only really began to realize how much trouble she was in when a strange-looking chair was brought in and she was told to take off her shirt in front of all these people. She and Mion didn't have any birthmarks or moles to immediately tip them off that this wasn't Mion shakily peeling off her shirt, but that didn't make Shion feel any less vulnerable under the eyes of her family, watching her like hawks.

She didn't know if Mion would've crossed her arms in front of her chest or not, and Shion didn't dare do anything out of character, especially not now. She wanted to, wanted to cover up her chest even though she hadn't really developed anything yet, because there was being naked to bathe and then there was this, and she didn't like it one little bit.

She was told to straddle the chair and lay on her front, and a strange-looking leather strap was put in her mouth "to bite down on," and she was guided to lay her hands over the arms, and her grandmother talked more and more as Shion understood less and less, as her unease climbed more and more, as she shivered under the cold of being half-naked in this basement. Four pairs of hands suddenly reached her, one to each shoulder and one on either side of her hips, and Shion's unease rose from prickling to screaming as these four adults pinned her down in the chair. Why would they need to pin her down?

A strange buzz filled the air –something that had nothing to do with bugs or insects, something that sounded nothing like the rattling hum of the cicadas in summer, but something familiar nonetheless, something a bit like the mechanical whir she heard sometimes at the dentist, though that sound was muffled through several walls and this was clear and right beside her. Why would there be a dentist's drill in here? They'd made her bite down on something, her mouth was closed and her face was pressed against the padding on the chair.

Then a searing pain jagged against her back, and Shion screamed and bucked on instinct alone, but the adults holding her still made sure that she only wiggled a few inches away. That burning, tugging, prickling dot of pain returned, scrawling busily over her back as Shion bit down on the leather strap, screaming through clenched teeth and trying to hold as much of it back as she could, not for herself, not because she wanted to be brave, but because she knew that if she somehow slipped up, if she didn't act like Mion, her family might kill her.

Sheets of blood ran down her back, sticky and hot, and whoever was doing this –whatever this was– had a rough towel that they used to briskly wipe the blood away, and Shion dizzily tried to focus on that, on the huge hands holding her down, on anything and everything but the prickling, piercing, tugging pain in her back, like someone was sewing a tapestry onto her flesh. She focused on it as hard as she could, until the world grew dull around the edges, and she realized that she was close to passing out.

Mercifully, it ended.

Shion wouldn't say it ended quickly –she'd spent hours in that chair of pain, hours in which her skin was burned and seared, and she probably had passed out once or twice, only for the ruthless jabs of pain to drag her back. But it did end, eventually, and a cool balm was laid over her back, sticky and smelling of sharp chemicals, and bandages were wound around her trembling torso before she was at last forced to move.

Pain flared all over her back, but Shion had come this far and she stood with a wobbling lip and teary eyes, trying very hard not to sway or just break down into full tears and collapse, as her grandmother did another speech. Then she was taken upstairs, and set very carefully on a cushion –nothing with a back to it, and oh, she wept in gratitude– as the promised banquet was spread before her.

Shion ate dully, trying to escape the throb of pain in her back as her relatives told "Mion" how well she had done, how brave she was, eating the sashimi that she had so begged for before all this began without really tasting it at all. The brief flashes of pleasure from her treat, from the praise of her relatives, only managed to dull the inconsolable agony spilled over her back, like someone had coated it in oil and then set it aflame.

She slept on her stomach that night, deaf to the inquiries of Mion, who at least didn't try to touch her, warned by the bandages and the sharp smell of ointment that something was wrong. She slept like that for almost a month, and during that whole time, she and Mion only switched places for the briefest snatches of time, with Shion going back to her old role and Mion regaining hers. They never did it around their family, who knew about Shion's back, and they could never do it for long, because they might be called in for more ointment to be applied to "Mion" before her shirt was pulled up and there was no injury there…

It took a month before the bandages came off for good and Shion actually had the time to look at herself in a mirror.

A glaring demon's head leered back at her from her back as Shion stared, ashen-faced.

There would be no more switching around the family, not with this.

9.31 PM, USA Central Time