Disclaimer: KHR! does not in any way belong to me, it's the property of Amano, etc.

Author's Note: High school!AU (oh, the cliché). Mukuro + Chrome are siblings, Muku is 18 (a high school drop-out) and Chrome is 16 (a sophomore), as is Haru. This story will eventually be Mukuro x Hibari.

Written for prompt 4 (leave me alone) of the lj community 10_orders. :)

And please forgive the laaaame title. Sometimes I think of really good ones. Other times I come up with something like this, aha...

An Older Brother's Prerogative

[ leave me alone. ]

Since he dropped out of high school two years ago to get a job and support his remaining family member (Chrome), Mukuro usually gets home from his shift to find Chrome waiting for him, dinner on the table more often than not.

Sometimes she stays late at school, or spends the evening at a friend's house, but in those cases she either texts him or leaves him a note.

The eighteen year old frowns when he sees no note on the table, and doesn't hear a greeting from his sister. She's obviously home, her shoes are sitting by the front door, but other than that the modest two-bedroom apartment seems empty.

Chrome's door is closed, so she must be there...

"Leave me alone!" Chrome shouts when he knocks on the door.

Mukuro feels one of his eyebrow twitch in annoyance. In general, Chrome is a cute, sweet little sister. This is one of those times when she falls into the much more troubling category of 'annoying nuisance'. It's been happening more and more recently, especially since she entered high school and started hanging out with that irritating Miura girl a year ago.

However, he is inclined to humour her this once, since he can hear the tears in her voice and her poorly muffled sobs. Whoever hurt his younger sister is going to die a slow and painful death. "Chrome-chan," Mukuro says with more patience than he really feels, "Please let me in."

Sniffling, his sister complies and then goes back to curl up on her bed, this time with her head in Mukuro's lap. He pets her hair a little awkwardly, not for the first time cursing the parents who abandoned them years ago.

"What's wrong, Chrome-chan?" he asks, handing her a tissue. "Did you and Miura-chan get in a fight?" This is the only possibility he has been able to come up with.

"N-no," Chrome answers, then blows her nose rather loudly.

Mukuro waits for her to continue, but his sister simply continues to sniffle. Irritating... he thinks.

"Did something happen at school?" he tries again.

Chrome nods mutely. Now they're getting somewhere.

"... Did it involve a boy?" Mukuro adds darkly, his eyes narrowing at the thought. It's hard to remember that his sweet baby sister is already sixteen, sometimes.

Again, he receives a silent nod in response.

"Who?" Mukuro demands furiously.

"H-he's a senior..."

Oh. Oh no that bastard didn't. Mukuro doesn't even know the kid's identity yet, but he does know that whoever he is, he doesn't have long left on this earth.

Chrome sits up and rubs a hand across her eyes. Her tears have abated, thankfully, though her eyes are still red-rimmed and her cheeks tear-streaked.

"Name?" Mukuro asks, shortly.

"Mukuro-nii, you can't hurt him," Chrome says sternly, the effect ruined when she sniffles loudly.

"I wouldn't dream of it," he lies, but Chrome knows him far better than that. He tries again, "I could always ask Miura..."

"Daemon Spade," Chrome mumbles, her fingers fiddling with the hem of her skirt. She hasn't even changed out of her school uniform. "B-but, it's not what you think, Mukuro-nii!" she adds quickly, when she sees the set of his jaw.

"Then tell me what happened. Or do I have to ask your annoying friend-"

"Just... um... Well, he asked me on a date last week..."

This is news to Mukuro. Last week Chrome only stayed out late once, and she told him it was to study with the Miura girl.

"...and I had a really good time, but today when I went to meet him for lunch like we arranged and he kept trying to, um," here she starts stammering, her cheeks flushing with embarrassment and distress.

Being an older brother, Mukuro's mind immediately goes to the worst places possible. He revises his earlier assessment: Daemon Spade has at least several weeks left on this earth ahead of him; too bad for him, he'll be in excruciating pain.

"Did he... force you?" Mukuro makes himself ask, not because he doesn't want to know the answer, but asking Chrome questions like this is a little awkward.

"He tried but- I slapped him and ran away."

"Good," the bluenet says vindictively.

Chrome smiles weakly. "I told the Discipline Committee... The vice chairman said they'd deal with it, so you don't have to do anything, ok, Mukuro-nii?"

"That doesn't mean I won't," Mukuro mutters, eyes narrowed.

His sister sighs. "Mukuro-nii... I'll go make dinner. We can talk about this after."

He nods, though he has no intention of being swayed. A senior, picking on his little sister? Unacceptable. The presumptuous bastard deserves to die.

Chrome leaves the room, and Mukuro notices that she left her phone behind. Smirking, he opens the contacts list and sure enough, Daemon Spade is near the top; Mukuro enters the information into his own cell phone, then carefully sets Chrome's back where it had been.

Pulling up Miura Haru's number, Mukuro quickly types, Good evening, Miura. I hope you're well. Chrome-chan is feeling a bit unwell at the moment – I hope it's not too much to ask you to come keep her company? I'm afraid I'm not very good at 'girl things'. – M. R.

The reply comes less than a minute later: Of course, Mukuro-san! Haru will be over in fifteen minutes. Chrome-chan didn't want to talk about what happened with Daemon-san earlier today and Haru didn't want to press...

Mukuro frowns. A few seconds later, he gets another: U-um, Haru means, unless you don't know about what happened with Daemon-san. Er, that is, nothing happened, Mukuro-san.

The bluenet rolls his eyes. What a stupid girl, he can't imagine what Chrome sees in Miura; but if she's happy, he won't complain. I know what happened, Miura-chan, don't worry about it. Please come as soon as you are able. I would greatly appreciate it. – M. R.

As the Rokudo siblings are sitting down for their meal, the doorbell rings and Miura enters without further invitation. The look Chrome sends her brother plainly conveys that she's not fooled, but she greets her friend easily enough.

Mukuro eats his meal quickly, answering in as few words as possible whenever Miura or Chrome attempts to include him in the conversation.

"Well, I'd better be going," he remarks casually after clearing his dishes away. "I promised Ken and Chikusa that I'd meet up with them tonight."

"Bye, Mukuro-san!" Miura says enthusiastically, with a cheerful wave to match.

"I'll see you later, Chrome-chan, Miura." Mukuro pulls on his black coat and walks out. He almost makes it down the hall, to the stairs, before Chrome runs after him.

"Mukuro-nii... Please don't do anything, um, rash. Just leave it alone, ok? The Discipline Committee can take care of things," his sister says earnestly.

The bluenet raises an eyebrow. The Discipline Committee he remembers from high school was a corrupt, ineffective institution run by corrupt, ineffective idiots. The head prefect was a blond named Dino, if he recalls correctly. But perhaps in two years this has changed. Nevertheless. "I don't get many chances to take care of you anymore, Chrome-chan. Indulge a protective older brother for once, won't you?"

Chrome bites her lip. "Don't do anything permanent to him," she insists.

Mukuro leans down and kisses her cheek. "I would never," he drawls.

"Yes you would, Mukuro-nii."

His lips quirk upwards into a smirk. "Good night, Chrome-chan. Don't stay up too long – I'll probably get home rather late."

A/N: Feedback of any sort is greatly appreciated. :D