Sleepy Princess in the Demon Castle
Sleepy Princess in the Demon Castle is a Japanese manga series written and illustrated by Kagiji Kumanomata. It has been serialized in Shogakukan's manga magazine Weekly Shōnen Sunday magazine since May 2016, with its chapters collected in 30 volumes as of August 2025. An anime television series adaptation produced by Doga Kobo aired from October to December 2020.
Plot
The story follows Princess Syalis, a young princess who was kidnapped by the Demon King, and her quest to sleep well while imprisoned. Despite the Demon King's best attempts, the princess turns her kidnapping into a vacation; having grown tired with the stress of a royal life, she is indifferent to the situation.Characters
;Princess Syalis;Twilight the Demon King
;Demon Cleric
;Dawner the Hero
;Quilladillo
;Frankenzombie
;Minotaur
;Castle Goblin Grunt
;Great Red Siberian
;Monster Shroud
;Ghost Shrouds
;Poseidon
;Fire Venom Dragon
;Neo Alraune
;Alazif
;Scissors Sorcerer
;Gearbolt
;Harpy
;Hades
;Hypnos
;Bussy/Cubey
;Queen Nemlis
;Teddy Demons
;Morgan
;Evening Star
;Ker, Ber, and Ros
;Tire Genie
;Ice Golem
;Neo Alraune's older brother
Media
Manga
Written and illustrated by Kagiji Kumanomata, Sleepy Princess in the Demon Castle started in Shogakukan's manga magazine Weekly Shōnen Sunday on May 11, 2016. Shogakukan has collected its chapters into individual volumes. The first volume was released on September 16, 2016. As of January 16, 2026, 31 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. On May 9, 2023, Viz Media launched their Viz Manga digital manga service, with the series' chapters receiving simultaneous English publication in North America as they are released in Japan.
An official fanbook of the series was released on October 16, 2020.
Anime
An anime television series adaptation was announced in Weekly Shōnen Sunday in September 2019. The series was animated by Doga Kobo and directed by Mitsue Yamazaki, with Yoshiko Nakamura handling series composition and Ai Kikuchi designing the characters. Yukari Hashimoto composed the series' music. The series ran for 12 episodes from October 6 to December 22, 2020, on TV Tokyo, AT-X, and BS TV Tokyo. Inori Minase performed the opening theme "Kaimin! Anmin! Syalist Seikatsu", while ORESAMA performed the ending theme "Gimmme!".Funimation acquired the series and streamed it on its website in North America and the British Isles. On February 21, 2021, Funimation announced the series would receive an English dub, with the first episode premiering the next day. Following Sony's acquisition of Crunchyroll, the series was moved to Crunchyroll. In Southeast Asia and South Asia, the anime is licensed by Muse Communication, and released on Bilibili in Southeast Asia. The series premiered on Animax Asia on May 12, 2021.
Reception
In 2017, the series was ranked 16th at the third Next Manga Awards in the print category.Anime News Network's staff included Sleepy Princess in the Demon Castle on their top 5 best anime list of 2020: Rebecca Silverman placed it at number four, praising the way the source manga gets cherry-picked and comes together as a whole, concluding that: "It's not only funny, but also one of the best adaptations I've seen, and I can't wait to start rewatching it as soon as it ends." Caitlin Moore placed it at number five, praising Mitsue Yamazaki and Yoshiko Nakamura for adapting the "already funny source material, tweaking the jokes, and incorporating split-second comic timing to make it outright hilarious."