Note: the events of this book are covered in the first one-hour episode of the OVAs, by chapters 1-19 (and a couple pages of 20) of the Arakawa manga, and roughly episodes 2-9 of the 2015 anime.
Chapter 1: The Battle of Atropatene
Chapter 2: Mount Bashur
Chapter 3: The Capital Ablaze
Chapter 4: Beasts and Beauties
Chapter 5: Successor to the Throne
* Although this illustration accompanies the first section, it’s more likely to be illustrating a scene in the second section.