Asō Natsuko appears in the mook (magazine / photobook) Anisong Angel (アニソンエンジェル) released on July 30.
Other anime song singers are also featured in the book : LiSA, Nakajima Megumi, Kurosaki Maon, Aoi Eiru, Yuki Aira, and more.
The mook contains photos and interviews.