(Y/n) Yamada was the twin sister Taro Yamada. They had always got along and would only occasionally fight. So when a new boy moves to the neighborhood, let's just say, a certain twin brother encourages (Y/n) and him to be together. But when a certain Yandere comes into play, secrets will be revealed.

"Volleyball is the most important to me", Oikawa said while rejecting you. He always considered having a girlfriend an obstacle in improving. So why did you see him kissing another girl?