S/O to the people who thought Ame was hella chill and sweet lmao no.

By Any Means Necessary

When Ame was nine, she got a boy expelled from her school.

He was older than she was, but not by much; maybe a year or so above her, but with a predilection for picking on those younger than he was, and chasing the girls who didn't want to be chased. Ema was one of those girls, and Ame had to run him off whenever he set his sights on her. However, on the days when she was placed in charge of tidying up the classroom during break, she could only watch helplessly as he terrorised her sister up and down the yard.

Telling the teachers did nothing. They brushed it aside as her being 'overprotecive', they laughed and said that 'boys will be boys' and 'how cute, maybe he has a crush on her!' But they knew nothing, and Ame was the one who had to comfort her crying little sister at the end of it all.

It was much easier than it should have been to get rid of him. Their principal's daughter was in her class. She was a pretty girl, taller than everyone else and better dressed too, and she had a ring she loved dearly. It was pink and shaped like a lotus flower, and she liked to tell them that it was a gift from her dad from when he took them to America on holiday. Most days of the week, her mother gave her a packed lunch, and since the ring was large and clumsy, she took it off so she could handle her chopsticks. Ame didn't think much of her actions until she dropped the ring into the boy's backpack, and then waited for it to be discovered at some later date. She would think about it much later, maybe mull it over for a bit, and then stop thinking about it.

A few weeks later the boy disappeared from their school. By the next month, the board of directors had appointed a new principal to replace the old one due to accusations of nepotism. On the playground, Ema smiled as Ame shared her octopus sausages with her under the cherry trees, and no one was there to chase her or make her uncomfortable. Ame had seen to that.

Ame would always see to that.

And yes time had gone by; she was older now, and she understood the moral ambiguity of her actions, but she wasn't sorry. Not as sorry as she ought to have been. In the grand scheme of things, Ema came first to her, and no one was going to touch her baby sister as long as she was around.

oOo

"Good day, Subaru-kun!"

He yelped, surprised by the sudden greeting, and then proceeded to choke and cough as the water he'd been gulping went down the wrong way. Ame detachedly applied a coat of gloss to her lips while he hacked up most of the liquid, and smiled sweetly once he was done. Subaru whirled around to face her. "Ame-chan! W-What are you doing here?" The labs and classrooms were across the campus, and unless your class or activities had to do with a sport of some sort then most people had little reason to visit the fields or gym.

The tube of pink shut with a quiet snap, and Ame blinked at him."Do I need a reason to visit my new brother? Especially since you might be playing in the next game."

"O-Oh…" he wasn't sure what else to say. Ame had been rather benign considering what she'd overheard the night before, but that didn't mean she was alright with him more or less inviting her sister out on a sort-of date to watch his match. His sister too. Step-sister technically, at least on paper anyway.

She must have been coming from somewhere else, and was dressed cutely in a pale pink collared dress, a blue cardigan, tights and black kitten heels. Her thick hair had been swept over her left shoulder, and pinned in place. Ame looked like she had just been on a date, or was heading for one. She was tapping at her cell-phone now, lips pink and shiny and curved in a smile that didn't quite reach her eyes. "I bet you're excited for that, aren't you Subaru-kun? I heard that there're loads of important people at these games. Scouts and coaches etc. Oh, but I don't think you care about that right now," Ame lifted her head and regarded him. "Do you, Subaru-kun?"

His face blanched when he saw the picture on her phone screen. It was the group wedding photo, the one they had all taken. There was only one in the house, hung up on the wall, and no one paid much attention to it. However Ame had cropped the image on her phone so that Subaru's face was the focus, and it was perfectly clear who he was staring at.

"It probably sounds romantic to you, doesn't it?" She commented casually, resuming her tapping. "You win the game and then, riding high on the the sheer adrenaline of victory, you sweep her off her feet and profess your undying feelings to her. It is romantic, but it's not going to happen."

Subaru's eyes narrowed, defiance beginning to replace the nervousness. "What do you mean by that? I have all right to tell Ema-chan how I feel!"

"Mmm, do you though?" Ame arched an eyebrow and slipped her phone into her bag. "Because I don't think you have as much right as you seem to think you do." She took a step forward, her heels clicking threateningly on the concrete. "In fact," she continued, backing him up against the side of the gym, "I happen to think that you have absolutely no rights to Ema's feelings whatsoever, apart from whatever she deems you worthy of! And so far, she considers you a brother, so you had better stick with that and enjoy it because I swear, if I hear that you've made my baby sister even the slightest bit uncomfortable, there will be dire consequences."

Anger and fear swirled inside Subaru. A part of him wanted to ask about these consequences, but the longer he stared into Ame's eyes the less he wanted to know. Gone was the sweet, innocent expression that looked so similar to Ema's, and in its place was something cold and ruthless. She didn't wait for him to agree or disagree, and simply spun around and walked off cheerfully. Her skirt hair swished at her thighs, and Subaru vaguely wondered if Kaname or Ukyo or any of the others knew what they'd got themselves into.

I would just like to add that Ame is not a bad person. Yes her actions may be morally ambiguous sometimes, but everything she does is for Ema's safety. She genuinely cares about the brothers, but Ema is a blood sister, and her love for her trumps her affection for them any day. If you're wondering why she's mean to Subaru, it's because in the original light novel Subaru is the one Ema ends up marrying in the end.