The Karasuno Kingdom celebrates the birth of the Fraternal Twins Kageyama the fourth prince and Hinata the youngest and only princess. The two were inseparable, wherever Kageyama goes Hinata will follow even if they fight a lot but when someone hurts Hinata, all of her siblings will protect her especially Kageyama. In the middle of the great war, Hinata decides to stop it and went to the kingdom of Shiratorizawa by herself. Ushijima as the Crown Prince of the Shiratorizawa knew about the princess' arrival, he asked his father to make her his bride. Hinata did as what Ushijima told her without complaining and risk her life to save the Crown Prince from the assassins. What will happen when Kageyama knew all what happened to his younger twin sister?