Kageyama Tobio was already feeling down knowing his classmates don't like him and he can't focus in his volleyball practice. Smile and being nice to people is easy but to him, it's not. But a little sister will show up in the middle of the semester. She's kind, pretty, smart, athletic, and talented. Will she be his friend or his enemy? "She's just simple," he said, "Just an ordinary stone," he walked away. *I don't own Haikyuu!