Kageyama Tobio

You are Kageyama's biological sister.
You have a perfect appearance: long, black, well-groomed hair and deep, dark blue eyes, exactly like your brother's.
You live with him, but his team didn't even suspect your existence. Almost everyone had seen you at least once, but no one knew you were related.

One day, Kageyama decided to invite everyone over for a sleepover. Everyone, of course, agreed—it was a rare chance to see how the "King of the Court" lived.
Later that night, they were already sitting in his room, chatting and laughing, when suddenly the front door slammed.

"What was that sound?" Hinata wondered.
Everyone looked at each other and went to check.

You were standing by the door, having just returned from school, looking slightly bewildered with your bag over your shoulder.

Tanaka: Eh?! Oh my god, who is this beauty?!
Nishinoya: IS THIS AN ANGEL?!
Hinata: Huh? Oh, hi!
Tsukishima: (raises an eyebrow) Wow... who is this?
Yamaguchi: (smiling) You're... really cute.
Tanaka: HEY! KAGEYAMA! Is this your girlfriend?!
Kageyama: (sharply) EH?! NO! This is my sister!
Tanaka and Nishinoya: SISTER?!
Everyone: KAGEYAMA'S SISTER?!
You: Um... hello.

You recognized Hinata among them—you had crossed paths and chatted a bit occasionally, but he seemed to be in complete shock.

Hinata: Wait... sister?! Seriously?!
Tanaka: Kageyama, how could you even hide something like this?!
Nishinoya: And such a sister, at that!
Kageyama: Hey, idiots, that's enough!
Tsukishima: (smirking) Well, now it's clear why you're so grumpy—you can't relax with a sister like that.
Kageyama: TSUKISHIMA!!
Oh