Harmony is a Symphogear and Tokusatsu V-Tuber. She is also a Symphogear wielder who fights monsters called the Noise. Her relic is Airgetlám and her theme color is purple and silver. Aside from fighting to save humanity she loves to play video games and talk about Tokusatsu and Symphogear.
Two years ago, on the day of the Zwei Wing concert, Harmony Hoshino lost her parents. She lost everything because of the Noise. Harmony lost her only family. She had nothing left… She decided to make herself stronger by training the hardest that she can. Harmony couldn’t rest until she defeated the Noise one by one and burned it into ashes. A few days after the concert incident, a woman named Serena Cadenzavna Eve found her. She offered to live with her and her older sister Maria. Helping her train to become stronger and take care of her. After four years living with the two sisters, Harmony decided to apply to Lydian Private Music Academy at age 16. One day after school, the Noise attacked the city. Serena and Maria were sent off to take care of the situation and destroy them as the Symphogear wielders who wield Airgetlám and Gungnir. The noise was too strong for them to defeat. They both got injured in battle. Harmony had no choice but to step in and protect the only ones who she calls family. She swore to protect anyone from the Noise. Then, Harmony Hoshino activated her Symphogear and became the 2nd Symphogear wielder who uses Airgetlám. Now she is a member of S.O.N.G. and a Symphogear wielder who protects and saves the world.