Suzu is a 17-year-old high school student living in a rural village with her father. For years, she has only been a shadow of herself. One day, she enters "U," a virtual world of 5 billion members on the internet. There, she is not Suzu anymore but Belle, a world-famous singer. She soon meets with a mysterious creature.

Together, they embark on a journey of adventures, challenges and love, in their quest of becoming who they truly are.