Sleepy Princess in the Demon Castle is a Japanese manga series written and illustrated by Kagiji Kumanomata. It has been serialized in Shogakukan’s Weekly Shōnen Sunday magazine since May 2016, with its chapters collected in seventeen tankōbon volumes as of December 2020. An anime television series adaptation by Doga Kobo aired from October to December 2020.
Sleepy Princess in the Demon Castle is written and illustrated by Kagiji Kumanomata. The series started in the 2016 issue #24 of Shogakukan’s Weekly Shōnen Sunday published on May 11, 2016. Shogakukan has compiled its chapters into individual tankōbon volumes. The first volume was released on September 16, 2016. As of December 18, 2020, seventeen volumes have been released.
Viz Media announced in September 2017 that they had licensed the series in North America. The first volume was released on June 12, 2018.
An official fanbook of the series was released on October 16, 2020.
Sshhh! Princess Syalis is trying to get a good night’s sleep. Some shut-eye. Forty winks. Catch some Z’s. Long ago in olden times when people and demons lived together in—well, disharmony, really—a demon king kidnaps a human princess and imprisons her in his castle. Bereft, the princess’s subjects beat their chests in anguish…until a hero arises to spearhead Project Rescue Our Princess! While waiting for her knight in shining armor, what’s an imprisoned princess to do…? Teddy-bear guards with bat wings are all very well, but her dungeon cell is bo-o-o-ring! So, she decides to wile away the long hours by sleeping. Now if only she could get comfortable…and didn’t suffer from insomnia…