Hisashi Kagawa × Yoshihiko Umakoshi - Batoru Hiroin Sakuga & Dezain Tekunikku (Yoshihiko Umakoshi - Battle Heroine Drawing & Design Techniques) was released by Genkosha MOOK in May 2017. It's an amazing book packed with drawing advice and rough sketches by the animators Hisashi Kagawa and Yoshihiko Umakoshi.
If you're into a certain anime, you probably already heard these names; otherwise, just know that Kagawa and Umakoshi were in charge of the character design for, respectively, Fresh Pretty Cure! and HeartCatch PreCure! In other words, no one is more qualified than the two of them to talk about "battle heroines"!
Due to the nature of this book, you'll probably find it has a deep anime taste that comes out both in anime original materials and drawings. However, advice that applies to anime also applies to illustration! If you want to learn how to draw dynamic illustrations, this volume and its contents will be critically helpful.
There are many art books about PreCure, but if you're looking for some niche advice and techniques - look no further! We would definitely recommend this book to both PreCure fans and to those who want to learn how to draw fighting girls.