Author's Note: For Ten-Faced :)

Who's That Girl?

Who's that girl?
Where's she from?
No she can't be the one
That you want
That has stolen my world

-Who's That Girl by Hilary Duff

"Wait, so like this?" Miku wondered, tapping her pencil against her page as Kaito leaned over to check. She stared at him curiously, but I couldn't help but think there was more than just curiosity in that gaze. As such, my eyes narrowed at her, which I only risked knowing that both she and Kaito were too busy thinking of their work to look up to the creaking of the opening apartment door.

Because I wanted his attention on me rather than her, I pasted on a smile and slammed the door behind me while calling, "Kaito!" as though I hadn't been standing there watching and wasn't well aware that he was sitting just steps away from the front entrance. I hoped he'd at least have the decency to stop sitting so close to Miku if he knew I was here, so I beamed at he and she together and offered, "I'm home."

"Welcome back," Kaito returned, though he didn't bother to hide Miku's presence. I felt my grip on the grocery bags tighten as I continued walking into our home, irritated. Didn't he care at all about how I felt? Jerk. It was bad enough that she was over her almost every night now. "Any luck finding reasonably-priced pork?"

I wasn't in the mood to discuss our shopping, especially not with Miku present. She had no place in our life together, so I didn't want her hearing any of this. So "No," I replied evenly, trying to stop the clipped edge slipping into my voice. I turned my back to them as I began to put the groceries away. My hands trembled as I did, but I refused to let that show. I didn't want to worry Kaito, no matter how much he was annoying me right. Once I'd gotten myself under control, I smiled sweetly over my shoulder and wondered, "Are you going to stay for supper, Miku?" because, if I didn't, I knew Kaito would, and he'd like me better if I played nice with his student.

I grew even more irritated with her presence when she spoke. "Oh, please, don't worry about me!" Miku exclaimed. She had a voice like a chipmunk, and she dressed and acted like a child. Kaito was three years older than her. I didn't understand how he could feel anything for her, which I was sure he did. "I should really be heading home some time soon, anyway!"

Then go already, I found myself thinking, though I'd grown so used to bitter thoughts like these that it didn't surprise me that I was so petty. She was just Kaito's tutoring student, after all, and a friend of his. I really didn't need to get so jealous, right? And Kaito was my brother, anyway, so shouldn't I be supporting his dating? It wasn't like there was anything really wrong with her, after all, aside from her taking up all of my brother's time.

"Nonsense," Kaito laughed, wrapping an arm around her shoulder. I felt myself grow tense, and my attempts to persuade myself not to hate Miku so much instantly diminished. Kaito barely even touched me anymore. He didn't hug me, he didn't pat me on the head, he didn't hold my hand like he used to when we were little. He probably didn't realize how little physical contact we had anymore. He had Miku, after all. "Ring doesn't mind, right, Ring?"

When he looked at me, though, seeing how expectant he was, I just smiled and said, "Of course I don't mind." I did mind, of course. This was our place, mine and Kaito's. Outsiders had no place here. This was the Shion residence, not the Hatsune residence. She didn't belong here. I wanted her gone. I wanted my brother back. "I was thinking of making curry for tonight."

"You're the best, Ring," Kaito cheered, causing me to blush. I was a little triumphant, because I knew that I'd beaten Miku here. There was no way she'd know that curry was his favourite meal, or so I thought until my big brother spoke a second time. "Miku cooked this awesome curry last week when I was over. She insisted when she found out it's my favourite. Maybe she could help you out and show you what she did."

Just smile, I told myself as Miku smiled sheepishly at his praise and told me, "I'd be glad to help you out if you need, Ring."

I kept my smile in place as I shook my head and informed her, "It's alright. I use our family's secret recipe, after all. That's something only Kaito and I can know. Sorry." Though I wasn't so sorry. I was glad Kaito and I still had this, after all. It was something he'd shown me and only me when we were younger; he'd said it was our secret and not ever to let anyone else know, not even our parents.

Kaito's laughter sent a cold chill through me, because the way he was laughing now told me what he'd told her. "Don't worry about that, Ring. I showed that to her when she was cooking for me last week." His smile turned to her then, and he stated, "She's my girlfriend, after all. She's part of the family now."

I froze in placing the vegetables in the fridge when I heard this. So it was official, then, was it? They were dating. Why did it bother me so much? Why was I so jealous? It wasn't like things were any different from before they were dating; they were still spending the same amount of time together. Maybe I was jealous that Kaito was dating someone when I still hadn't even had my first kiss at seventeen? But, no, it wasn't that. I was jealous of her. I was jealous of Miku. How? Why? Why was I jealous of her?

I pulled back from the fridge and shut its door, telling Kaito, "I forgot something. I'm going back out to the supermarket. I'll be back soon." I didn't truly listen for his response, nor did I bother looking to see how Miku reacted. I could feel that I was about to cry, and I had to get out of there before Kaito noticed.

I didn't understand it, though. Why did hearing that Kaito and Miku were dating hurt so much? Hadn't I been expecting it all along? It shouldn't be that big of a deal, anyway. I should've been teasing them or telling them how cute they were, like any other little sister would. After all, I had to admit that they were adorable together. Why did it bother me so much to see them together? It wasn't like I was jealous of Miku, right? I had to be misunderstanding something. Just one of those stupid girl emotion things, right? After all, if I really was jealous of Miku, what would I be jealous of?

Well, actually, that was easy, and I hated it.

I was jealous that Miku got Kaito's attention. I was jealous that someone else was able to make Kaito smile. I was jealous that Kaito was sharing secrets with Miku that I'd thought were ours alone, that he didn't come home early and watch television with me anymore, that he didn't tell me he loved me every time he left the house seeing as Miku was always with him when he left now. I was jealous that she'd somehow managed to steal him, because I knew that I'd never have been able to do that. I was jealous that he told her she was pretty. I was jealous that she loved him. I was jealous that he loved her. I was jealous that they were in love.

Why, though? Why was I jealous of that? I was his sister; these weren't things I was supposed to be getting jealous over. His girlfriend, girls who liked him, his exes: those were the people that should have felt that way in this situation. Not me. I was his little sister, with the same blood in my veins as he had in his.

There was that, at least. Miku could never share the same blood as him. Still, at the same time, I cursed sharing his blood. After all, that meant I couldn't love him. No, wrong, I could love him. Of course I loved him. He was my brother. He was family. Of course I loved him. But, no. This wasn't the same love I felt for our dad, for our cousins. My love for Kaito just felt . . . different. It didn't make sense. Maybe it was just that he was my brother?

Or maybe it was just me denying it. That love I felt for Kaito, I saw it when he looked at Miku, when she looked at him. I loved him that way. I loved him in a way that wasn't the way I should love him.

I couldn't stop myself from turning around and going back to the house. I couldn't stop myself from walking in the front door, opening to a scene they hadn't meant for me to witness. I was supposed to be gone, after all, so of course it wasn't strange for them to be making out. They pulled apart when the door opened, though, and I felt the heat from Kaito's cheeks at the way from the kitchen table to the front door.

"You're back quick," Kaito chuckled embarrassedly, but I simply glared at him. I couldn't stop myself, even after he flinched and made guilt rise in my chest. He was horrible. How could he replace me with someone like her?

"Why is she here?" I wondered quietly, staring darkly at him. How could he? How could he let her into our house, share our secrets, expect me to take care of her like I did him, expect me to sit her and smile while she lived the life I wanted?

"What do you mean?" Kaito wondered, looking incredibly thrown off by my harshness. Miku was frozen stiff, not comprehending the situation in the least. I couldn't blame her. It wasn't her fault. "She was here when you left."

"No," I replied slowly. "She shouldn't be here. You shouldn't be with her."

Kaito blinked slowly at me, completely lost. "Ring, what are you talking about?" I was crying, I realized when I saw sadness shining in his gaze as he murmured, "What's wrong, Ring?"

Instead of answering, I simply took those steps over to him. My heart was pounding, so I had to simply stand in front of him for a fair while until I could gather the courage I needed to do what I'd always wanted to do, what I'd always denied to myself. I slowly lowered my face to meet my brother's as he sat in the chair in front of me and pressed my lips softly against his. I pulled away after that and stared into his mortified eyes. I smiled softly, continuing to cry silently, and informed him, "I'm not sorry."

I turned around after that and fled from the house, losing myself in the streets of downtown so that Kaito couldn't find me even if he tried. He tried calling a few times; I listened to every message her left. Finally, I answered, ignoring his frantic questions and simply saying over his voice, "I won't be coming home anymore, Kaito. Not if she's around."