Sleepy Princess in the Demon Castle

Sleepy Princess in the Demon Castle

Sleepy Princess in the Demon Castle anime series cover art
Sleepy Princess in the Demon Castle

Series Overview

Sleepy Princess in the Demon Castle (Maoujou de Oyasumi / 魔王城でおやすみ) is a slice of life comedy series in a fantasy setting. The series is about a young princess who’s kidnapped by a demon lord and kept as a prisoner in his castle. Except, she’s not much of a prisoner at all.

Princess Aurora Suya Rhys Kaymin, simply referred to as the princess, loves to sleep. Unfortunately, the conditions she’s initially kept in at the Demon Lord’s castle make it impossible for her to get a good night’s rest. And so, the Princess sets out to make her cell within the Demon Lord’s castle more accommodating to her needs.

In order to make her cell more comfortable, the Princess regularly escapes and wanders the halls of the castle in search of materials. These materials range from powerful magic items found in the castle’s treasury to the mutilated corpses of the castle’s demon inhabitants.

The Princess sleeping from the anime series Sleepy Princess in the Demon Castle
The Princess sleeping

The series features three main parties that are each trying to come out on top. First, is the aforementioned Princess who just wants to sleep. Second, is the Demon Lord and his minions who want the Princess to act more like a prisoner and stop leaving her cell. And third, is the Hero attempting to rescue the princess.

At first, you’d think that the dynamic between these three parties would be pretty straightforward. But in reality, things are a bit more complicated. The Princess isn’t really concerned about being saved from the demon castle. And in fact, she hates the Hero and doesn’t want to be saved by him.

Then, while the demons want the princess to act more like a prisoner, they begin to view her as their own princess who needs to be protected (mainly from herself).

Demons of the Castle

Demon Lord Tasogare is, obviously, the Demon Lord who reigns over the castle. But, he’s not like most demon lords you may be familiar with. In this series, the Demon Lord is very much concerned with how he and his castle are perceived.

He wants to be viewed as an evil entity despite that not really being who he is. For example, when the Princess keeps leaving her cell to gather materials to make it nicer, the Demon Lord complains that she’s not acting like a proper prisoner. He doesn’t really stop her from wandering the castle, but he wants her to at least give off the impression that she doesn’t have free reign.

The Demon Cleric is another one of the primary demons within the castle. He’s often the voice of reason among the demons because he understands the princess the best. And by that, I don’t mean that he understands her wants and needs. I mean he understands that the princess is a danger to herself and everyone around her.

The Demon Lord and Demon Cleric from the anime series Sleepy Princess in the Demon Castle
The Demon Lord and Demon Cleric

Great Red Siberian is about on the same level as the Demon Cleric, being just below the Demon Lord himself. I guess he’s supposed to be a werewolf, but he just looks like a husky beastman. While the Demon Cleric is in charge of religious services, Great Red Siberian is in charge of the day-to-day operations of the castle.

There are also a variety of other demons and monsters living in the castle whom the Princess befriends and/or uses. My favorites of the other demons are definitely Harpy and Sakkyun (mostly because they’re cute girls). And as far as the random monsters go, I think Ghost Shroud is the best.

Highs and Lows

Most seasonal anime have the same problem for me. By the halfway point of the season, I get pretty tired of a lot of the series I watch. That’s partially because I do knowingly watch some bad or mediocre anime each season. And it’s also partially because having to wait a week between episodes is a drag.

So, if you were to look at my ratings on MyAnimeList each week, you’d likely notice that my average score for the season decreases. I tend to rate things higher right when they start because they’re new and exciting. But by the end of the season, my scores have mostly fallen to where I think they should be.

And of course, there also may be a small number that actually increase in score over time. Within the current season, I’d say that Jujutsu Kaisen is one of those series.

Sleepy Princess in the Demon Castle is very unique in how my opinion of it changed over time. I enjoyed it well enough at the start, but by the middle of the season, watching the episodes really became a chore. I just wasn’t enjoying the series all that much anymore. Sounds normal so far based on what I’ve already said.

However, what I wasn’t expecting was for this anime to have a late-season resurgence. The final third or quarter of the series was probably the best part. Normally, I would think a series gets worse or better as it goes on. But this one got worse before coming back stronger than ever.

Basically, the Princess gathering materials and leveling up her cell got a bit old. But once the demons rallied around her as effectively their own princess, it created a new dynamic that freshened up the series.


Sleepy Princess in the Demon Castle is a 6/10 for me. The beginning was around this score, the middle dropped to maybe a 4/10, and I think the end might have reached a 7/10. So overall, I’m giving it a 6/10. It was an enjoyable anime even though it dragged in the middle portion.

Also, the OP and ED for this series are both great. Inori Minase voices the Princess, and if you’re familiar with her, you may know that she basically always does an OP, ED, or insert song for every anime she’s in. For this one, she sings the OP and it’s great. The ED isn’t her, but it’s still a fun song with cute visuals.

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