Sleepy Princess in the Demon Castle

Sleepy Princess in the Demon Castle (魔王城でおやすみ) 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.[4] 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 (スヤリス姫)
• Princess Syalis (full name: Aurora Sya Lis Goodereste) (オーロラ・栖夜・リース・カイミーン) is a princess who was kidnapped by the demon king and causes chaos in the demon castle while trying to get a good night's sleep. She has been living at the demon king's castle for a year now due to her wishing to escape the stresses of royal life and making no intention to escape. Before long, she begins accepting the demon castle as her new home.
• Twilight the Demon King (魔王タソガレ)
• The leader of the demon race, who is also the one responsible for abducting Syalis. He is usually annoyed by her antics and sometimes get dragged into them. Despite being the Demon Lord, he's not all that intimidating or ruthless.
• Demon Cleric (あくましゅうどうし)
• A demon priest who has the power to bring those who were killed back to life. Most of the time, he had to revive Syalis after she accidentally kills herself or those that she killed for her own means. Like Twilight, he also sometimes gets dragged into Syalis's antics. He seems to have feelings for Syalis as he gets very jealous when anyone else has feelings for her.
• Dawner the Hero (勇者アカツキ)
• Dawner is the hero who is entrusted by the Human Confederation of Goodereste with the task of saving Princess Syalis from the demon castle. Although Dawner and Princess Syalis are childhood friends and also engaged, she does not remember who he is. Whenever she mentions Dawner to the denizens of the demon castle, she calls him, "Daw-What's-His-Name". Due to Dawner being outgoing and friendly to Princess Syalis, yet being incredibly clumsy and prone to mistakes, he had always annoyed her, thus causing her to have nightmares when at one point he enters her dreams. He is also known for his poor sense of direction, which explains why Princess Syalis has been captured for a year, along with Syalis' unwillingness to escape.
• Quilladillo (はりとげマジロ)
• One of Twilight's henchmen. He resembles a porcupine.
• Frankenzombie (フランケンゾンビ)
• One of Twilight's henchmen. He resembles Frankenstein.
• Minotaur (ミノタウロス)
• One of Twilight's henchmen.
• Castle Goblin Grunt (やしき手下ゴブリン)
• One of Twilight's henchmen.
• Great Red Siberian (レッドシベリアン・改)
• Loyal retainer to the Demon Lord, in charge of enforcing rules. The princess drives him batty by her blatant disregard to the fact she's supposed to be a hostage. In fact, later in the series, he notes that Princess is costing them a fortune with all her misadventures; adding onto the woe everyone endures.
• Monster Shroud (おばけふろしき)
• He and his subordinates are the principal victims of Princess Syralis's antics, especially when she needs cloth to make things to get a good sleep. The death of the Ghost Shrouds by the Princess is a common joke in the series.
• Ghost Shrouds (おばけふろしき)
• Monster Shroud's minions.
• Poseidon (ポセイドン)
• A demon who has dominion over water. Because Poseidon never wears a shirt, the princess labels him a nudist.
• Fire Venom Dragon (かえんどくりゅう)
• A demon who has dominion over fire. He always wears a mask.
• Neo Alraune (ネオアルラウネ)
• A gentle plant demon, whom has motherly concern for the Princess. While willing to overlook all the deaths the Cleric is forced to undo, Neo Alraune became "miffed" upon realizing her tree trunk brother killed by the Princess as part of one her usual ridiculous sleep plans.
• Alazif (アラージフ)
• Spirit of a forbidden grimoire the princess freed by sheer dumb luck. Alazif tries encouraging Syalis to use his powers to defeat the demons and leave the castle; however, she is left severely disappointed with her due to her preoccupation with sleeping.
• Scissors Sorcerer (シザーマジシャン)
• A demon with an arm made of scissors. Syalis gave him her crown to keep his arm together in exchange for his lost scissors; unfortunately, leading to her routine of killing the ghost shrouds.
• Gearbolt (ギアボルト)
• A scientist demon.
• Harpy (ハーピィ)
• A harpy who believes that the princess considers her a friend over a misunderstanding with Syalis wishing to nap on Harpy's feathers.
• Hades (ハデス)
• Poseidon's older brother. Hades is always looking for chance to usurp the throne if Twilight messes up bad enough because of their mutual grudge.
• Hypnos (睡魔)
• A sleep demon; he must sleep 20 hours a day or risk death. Hypnos was called to examine Syalis' nightmare at one point; revealing to the demons just how much the princess detests Dawner (the source of the nightmare).
• Bussy/Cubey (さっきゅん)
• A succubus who looks eerily like the princess; only she has purple hair and gold eyes. Cubey wished to learn why the princess was so popular despite looking the same, but got sucked into being trained as her double.
• Queen Nemlis (カイミーンの女王)
• Nemlis (full name: Aurora Nem Lis Goodereste) (オーロラ・音無（ネム）・リース・カイミーン) is the queen of Goodereste, a kingdom of humankind, and mother of Princess Syalis.
• Teddy Demons (でびあくま)
• Living teddy bears with wings. Syalis keeps one as a pet and bribes them into giving her the keys to her cell in exchange for being brushed. They soon develop a good relationship with her.
• Morgan (モルゲン)
• A muscular paladin who works in Goodereste's castle.
• Evening Star (ミョウジョウ)
• A paladin who works in Goodereste's castle. He is only awake at night and falls asleep when its daytime.
• Ker (ケル), Ber (ベロ), and Ros (スゥ)
• Hades' subordinates. They are a trio of wolf demons.
• Tire Genie (タイヤ魔神)
• A demon whose body is made of tires. Should his body be missing, he appears in gaseous form.
• Ice Golem (アイスゴーレム)
• A demon made of ice cubes. He is the leader of the ice demons.
• Neo Alraune's older brother (わるもくじん)
• Neo's unnamed older brother who is a demon that resembles a tree stump. Even when his body is cut up, he does not die so easily.

Media

Reception

In 2017, the series was ranked 16th at the third Next Manga Awards in the print category.[113]

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."[114] 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."[115]

External links