One day, Charlotte Bennett comes to study abroad in Akihito Aoyagi's class.

All of his classmates are attracted to Charlotte's innocent, elegant behavior and cute appearance, but Akihito calmly feels that she lives in a different world and takes a step back. However, when he helps Charlotte's younger sister, Emma, who was lost, Akihito's daily life changes drastically. After finding out that the Bennett sisters live in the next room of the apartment building, and also that Emma has grown fond 