Ai is a young woman who wakes up with no memories besides her name and the vague notion that she is a princess from another world. In her confusion, she stumbles about the streets of Shinjuku until she encounters a young man named Kent. She is immediately charmed by his kindness, and eventually ends up accepting his offer of shelter. As Ai tries to piece together her forgotten origins, it becomes clear that she possesses a passion for music and a singing voice that captivates those around her. But enemies from Ai's former home are in pursuit of her, and she must hurry to understand her role in an otherworldly conflict she cannot even remember. [Written by MAL Rewrite]