She is a spirit that follows Necrodiver (Shu, Aiba)  and helps him fight.

In A.D. 2031, humans are enjoying a prosperous existence until strange life forms called Hardians appear. They suddenly begin to multiply and assault the human population. As a countermeasure, mankind organizes the N.I.D.F. to investigate the Hardians and protect themselves. 
A fighter pilot, Aiba Shu, begins to become involved in the battle against the lifeforms. Rurika Yuno, one of Earth's foremost scientists, investigates the Hardians and hears rumors about the "Book of a Dead Man." What is the secret of this tome, and what relation does it have to the Hardians? 
Now, the fight for mankind's survival begins. 
(Source: AnimeNfo)

[Twitter](https://twitter.com/akekodao) | [Agency Profile](http://amuleto.jp/talents/AkesakaSatomi.html) | [Blog](http://blog.animate.tv/akesaka/)

Satomi got her start in show business in 2001 when she won the "Idol Grand Prix", an idol contest sponsored by the manga magazine Nakayoshi. She became an event character for the anime "Tokyo Mew Mew" by joining the group Mew Five. She made her debut as a voice actress in 2004 in with role of Anzai Futaba from Koi Kaze, and as a stage actress a year later. She released her first single "Akeban!" in 2011. As a part of the BanG Dream! project, she also played the keyboard for the band [Roselia](https://anilist.co/staff/153170/Roselia) as the character Rinko Shirokane up until September 2018, when she was forced to quit after suffering sudden deafness twice. Before Roselia, she had been playing the piano since a young age, and previously played classical music.

Satomi's hobbies include using computers, drawing, reading, gaming and sleeping. Her favorite food is umeboshi, and she loves animals, especially cats.

(Source: BanG Dream! Wiki, edited)

Varda