This is one with a unique premise: ten years after defeating the Demon Lord, the hero is a disgraced nobody. The Demon Lord resurrects, can’t stand being denied a truly glorious rematch, and thus becomes the “coach” figure trying to get the hero back in shape. It doesn’t seem like a bad core for a screwball comedy, so what’s the result?
After a dramatic defeating of a monstrous demon lord, we cut to ten years later, where the Demon Lord has resurrected as… some kind of chubby blue-haired kid with three eyes and horns. Taking his/her status in stride, the demon lord chats with the one minion who has remained active over the years, a dubiously dressed demon secretary called Zenia.
The shots of Zenia let you know something of the show you’re in for.

Eventually, the demon lord rockets off to the human realm to announce her(?) revival to the hero responsible for the previous human victory, Max. However, it turns out that Max is now a washed-up nobody living in a squalid and seemingly haunted one-room apartment, through both his own foibles and the cruelties of a society that no longer needed him being reduced to the lowest of the low. Of course, the Demon Lord isn’t doing so hot either, seeing as his(?) premature resurrection seems to have resulted in a lack of supernatural prowess as well as a lack of stature.
By the end of their interactions, the Demon Lord decides that to have a satisfying world conquest, Max needs to get back in shape. And the Demon Lord is going to make sure it happens first-hand.
Since the show can’t go without some eye candy, it’s very quick to introduce the demon lord’s “disguise” form (green-haired schoolgirl whose sailor top barely covers her breasts) and bring Zenia back into the mix (it turns out she really can’t hold her liquor).
The former party cleric, Fred, now a government official, drops by shortly after. He’s there to discuss the brewing civil war with a breakaway republic under the party’s warrior, Leo. He also tries to blackmail Max but it turns out that the haunting is worse news than the presence of a petty-level demon lord, so discovering that sends the cleric packing
Most characters can’t sense the ghost, with even the demon lord only sometimes hearing her. The cleric, on the other hand, is scared out of his mind
This causes the demons to try to recruit Max, first via matchmaking (Max isn’t into monstergirls and Zenia has a horrible personality, which leaves an awkward moment around the Demon Lord’s sexy schoolgirl form) and then by employment offer. After the comedic pitch, the rejection is actually heartfelt, and I feel like that’s a big part of this show.
Specifically, the show has a huge range. Even in just the first few episodes it goes from “naked people are funny” jokes and shamefully obvious fanservice to tough geopolitical drama and philosophy. And it slides between these elements like butter in a frying pan; the transitions are often pretty much nonexistant. Like right after Max actually sounds vaguely cool in his reasons for turning down a fairly good be-a-demon deal, we cut to him failing catastrophically as streamer until putting the demon king (schoolgirl mode) on camera gets too spicy for the setting’s Youtube knockoff.
And then it’s right back to geopolitics as some of Leo’s minions try to recruit Max to join their side in the brewing civil war, with important-sounding talks about how Leo’s people worked hard to better their living situation and got screwed over when a special ore was found in their land. You know, the kind of stuff that doesn’t exactly mesh with the former hero and schoolgirl demon lord going on “absolutely not a date”.
Thanks to the demon lord being petty, the encounter results in them taking a vacation to Leo’s new republic. Since this requires the Demon Lord being in disguise most of the time, it’s mostly a setup for doing Hero/Sexy Schoolgirl Demon Lord Rom Com antics

They see the border conflict as well, including that the rebels are doggedly using nonlethal weapons. Once they return home (after an encounter with Leo), we focus on Fred having a dealing with a sleazy councilman, and a bomb going off at the Ministry of Magic probably thanks to said councilman, which Leo’s people are framed for.
This becomes the backbone of our entire final arc, which is centered around Fred going to the Republic to call out Leo and defeat him in single combat for the sake of geopolitical expedience, while Leo fights back for the same of honor. Max is initially uninterested, afraid to choose a side and kill one of his friends or the other, but the demon lord rockets off to interfere (and gets shot down) and Max reflects on a gift from the fourth original party member, the wizard Yuria, who can’t be involved personally for reason of pregnant.
Thus, Max manages to get in the middle of the fight by way of supersonic pedaling of a childish bicycle with the resolve and a little secret weapon to drub both his former friends unconscious and make a plea to the world (watching through news broadcast) to make some sort of diplomatic peace so that a literal war between the party of the heroes is no longer needed.

This works out pretty well. Everybody goes home, hot schoolgirl demon lord flirts with Max, the ghost gets jealous not that anybody can see or hear it, massive public opinion forces the kingdom to recognize the republic and normalize relations, albeit as an “autonomous province”, and Zenia screwing up leaks data from the ministry of magic that proves the creeper councilman who arranged the bombing guilty of massive fraud, resulting in Fred being given his elite posting.
Thus, the comedy continues.
The strength and weakness of this show is essentially the same thing – it has three modes that it can effortlessly flip between to do different content. Mode one is the screwball ecchi comedy about a washed-up hero and relatively powerless demon lord trying to get his arch rival back into shape. Mode two is this serious deconstruction of fantasy archetypes, showing cold geopolitical realities and the fact that the peace they won hasn’t been kind to the former heroes who saved the world. Happily ever after was not as happy nor did it last as long as people thought. The third mode is this weird romcom between the Demon Lord and the Hero that sort of bridges the gap between the screwball side and the down to earth side.
Even now, it’s hard to say whether or not I actually liked it, because in part it’s hard to say just how much the show actually thought out. Like, right off the bat when episode one gets to the present we are treated to an extremely over the top camera focus on Zenia’s nether regions in her weird swimsuit-business-suit. Is it unironically shoving the fanservice in our faces to that degree? Or is this supposed to be a parody highlighting how it’s impossible to take Zenia seriously?
This isn’t like Konosuba. I know in that show, when the camera admires the girls, it’s doing so unironically because Kazuma is probably doing it unironically. Here, I’m not sure if it’s stupid enough or smart enough for either option.
Similarly, when the show talks about the kingdom being a jerk and eminent domain yanking the land that Leo and his crew more or less single-handedly developed, did they actually feel like creating something that felt real in terms of a national scale conflict, or did they stumble into it? That one seems on the smarter end but the world may never know.
In the end, I do think I was entertained by Level 1 Demon Lord & One-Room Hero. When it wanted to, it had depth and complexity, enough that I don’t think it would be easy to stumble into it. I especially appreciate that while there is the one jerk on the royal council, he’s barely in this and probably didn’t even need to be there to get the conflict going; essentially, there’s no “antagonist” so much as the opposed wants and needs of two powerful forces, neither of which is entirely right or wrong. I think there’s more sympathy for Leo’s side than Fred’s, but there are still some good points made about territorial rights and international woes such that you believe the kingdom officials think they have to go the heavy handed route.
Still, I think I can only give this one a C+. At times it strives higher, and oddly I think this material could have done amazingly well as the drama it pretends to be about a third of the time, because the comedy often comes off as more half-baked. It’s not the worst slapstick and it’s not all utterly reliant on ecchi, but it isn’t great either. The romance angle is also a bit half baked because the hero and demon lord seldom relate to each other as such. There isn’t a sense of enmity, because we establish in the first episode that Max is more than willing to treat that as water under the bridge thanks to his being burnt out. By the time they’re going out and about with the demon lord in sexy schoolgirl mode, she’s more of an annoying acquaintance than an old enemy or even a rival, and his kind of tsundere reactions to her not really listening to things like “Go home and leave me alone” doesn’t have much of an undercurrent to it. Given all that, C+ is a blessing.