But she won't just be singing. The talented Koeda has done the music and lyrics for all eight songs on the album. Ryo of Supercell said early on that he could not really control Koeda, and ended up not even trying. He considered her brilliant, as I do, and let her come up with her own nuances in each song.
I think Koeda is a brilliant new voice: powerful, musical, and inventive. I'm not even surprised that she is writing her own words and music, since she already did a couple of good songs and posted them on her SoundCloud page.
She is writing the new songs, but ryo is doing the arrangements.
The debut concert will be at Tsutaya O-West in Tokyo on June 28. This is a small hall with 200 seats and a capacity of 600 total. I don't believe she has done live performances before, at least not professionally. If I lived in Japan, I'd be applying right now to be selected for a ticket.
Here are a couple of videos of Koeda with Supercell. She began singing with them at 15, so the early videos conceal her face to some extent. It is hard to find pictures of her except by taking screen-caps of the half-hidden views in some of the videos. But she has revealed herself more in some of the more recent videos, and perhaps now that she is 18 she will come out into the open. But she is a musician rather than an idol, so she may remain a bit behind the scenes.
Koeda is fairly active on Twitter. She has replied to tweets in Korean before now, so I wonder if she is of Korean ancestry. She is so behind the scenes that there is not even a Japanese Wikipedia page for her yet.
From what little I've read in forums, she is a controversial singer. It appears that many people do not appreciate her wild creativity. She may be a little too creative to ever be very popular, but I consider her brilliant, and musically far above most (or perhaps all) other singers in the anime music realm.
The CD will be released on the Lastrum label. Here is the CD's page on Amazon Japan.