Natsu Hyuga Added Material To Apothecary Diaries Season 3
Season three is the point where the anime runs past its manga adaptation and has to carry the novel material on its own, which is why the author stepped in alongside director Akinori Fudesaka and composition writer Norihiro Naganuma.
Reporting from 1 source: Animehunch.
Natsu Hyuga said on her official X account that she contributed additional material to the third season of The Apothecary Diaries so the story would not feel weaker than season two. The manga adaptation is still on the Shi clan rebellion arc at chapter 88, leaving season three to adapt light novel volume five without a storyboarded manga template.
The manga adaptation by Nekokurage and Itsuki Nanao is still closing out the material that season two adapted, at chapter 88 in the Shi clan rebellion arc. That left season three to adapt volume five of the light novel directly, with no storyboarded manga pages to work from. Hyuga wrote that the setting also shifts to a stage with a different scale from the first two seasons.
Synthesized by Yomimono from the 1 cited source below, including Japanese-language reporting where cited, then editorially reviewed before publishing.