Koshin Aki (Aki Koshin) was one of the children Izumi met while her prism shows. Koshin had a love for prism shows, so she was accepted in Edel Rose. Koshin is a sexy-type prism star. Her theme color is brown. She has red-orange side-tied hair, so she strangely looks like Nozomi. In the future, Koshin is one of the primary characters of Ethel - ROSE along with Riri Kurin , Uro Atsayami and Momoka Bashi.
- Koshin is a fan of Nozomi, so maybe it's because Nozomi that she ties her hair in a side way.
- According to the manga, Koshin originally had blue hair, so maybe being Nozomi's fan, she wanted to look like her, and died her hair orange-red.