We learned back in September 2019 from the Weekly Shounen Sunday magazine that an anime adaptation of the Sleepy Princess in the Demon Castle manga from Kagiji Kumanomata is in the work with a 2020 debut planned for it. The official site has now updated to reveal some new information along with a key visual you can see below. Mitsue Yamazaki is directing the series based on the series composition by Yoshiko Nakamura. Ai Kikuchi is working on the character designs with Doga Kobo handling the animation production.
The first round of casting has revealed Inori Minase as Princess Syalis.
The manga began in 2016 in the magazine and there are twelve volumes out as of this week. Viz Media has the North American rights to the manga and brought out the eighth translated volume last month.
Plot Concept: She decides to while away the hours by sleeping, but getting a good night’s rest turns out to be a lot of work! She begins by fashioning a DIY pillow out of the fur of her Teddy Demon guards and an “air mattress” from the magical Shield of the Wind. The princess’s hapless demonic guards soon discover that their captive expects to be treated like, well, a princess. Things go from bad to worse — for her captors — when some of Princess Syalis’s schemes end in her untimely — if temporary — demise and she chooses the Forbidden Grimoire for her bedtime reading…