The Binfield Kingdom Chronicle recounts that there was once a small, peaceful nation known as the Kingdom of Winfield, where the king and his royal family possessed great white wings. Hamura Shou has just enrolled at Yuusei Academy. After the headmaster mentions a student named Misonou Kai, Shou comes to believe that Kai is his younger twin brother, from whom he was separated in his youth. However, following a mysterious earthquake, Shou is suddenly transported to another world along with two other students. It is in this new world that, after being attacked by a monster, Shou suddenly unleashes great, white wings.