TV-Series
Description
Misora Hibiki is an 11-year-old international pop sensation known as Sonia Strumm. She wields a guitar-shaped device serving as her Transer, later upgraded to a Star Carrier while keeping its guitar form. Her distinctive look features purple hair, a pink hoodie adorned with a musical note emblem, green shorts, and blue boots.

Her mother's death prior to the series deeply influences her emotional bond with music, leading her to compose songs as tributes. This loss creates a connection with Subaru Hoshikawa, who also experienced parental absence. Hibiki harbors romantic feelings for Subaru, though he remains mostly unaware of her affection.

Partnered with the EM being Lyra, she undergoes EM Wave Change to become the superhero Harp Note, wielding sonic-based combat abilities. Initially fighting Subaru and Warrock due to misunderstandings, she later forms a BrotherBand with Subaru, becoming steadfast allies. Her personality blends cheerfulness and mischief with seriousness during conflicts, showcasing adventurousness and protectiveness, particularly toward Subaru.

During the "Tribe" storyline, she accompanies Subaru and Warrock on a global mission to secure OOPArts and prevent the ancient Mu continent's resurrection. She directly opposes antagonists like Doctor Orihime, Hyde, and Gori Monjirō, battling to thwart their goals. Events in the second game see her briefly ally with antagonists under false promises that Subaru would be unharmed. Discovering the deception, she severs her BrotherBand with Subaru to protect him, resulting in critical injury and hospitalization. After recovering, she reconciles and rejoins his team.

In later continuity, she allies with the Satella Police under Project TC as registration number 004, balancing her music career with superhero duties. She invites Subaru and friends to her performances, where they often confront threats like Diamond Ice. She participates in events such as a charity swimming contest and travels with Subaru during investigations into phenomena like Noise corruption and Dealer operations.