Yes, this is a fantasy nukige visual novel H-game with a 2 episode anime adaptation, but it still has a surprisingly interesting story, which begs the questions...
WARNING - Many spoilers are not marked here!
- Both sides are said to have ample reasons to view each other in positive AND negative lights, but there are so many parts of it that seem to be contradicting, such as King Hagel I marrying a Nymph and keeping her identity as a demon (as well as their daughter's identity as a half-nymph) a secret from everyone rather than just rescinding and removing the "Demon Extermination Order" like Lute does when HE eventually becomes king so he could openly marry Shamsiel?
- Humans seem to see demons as monsters for their appearances and magical abilities. Even Shamsiel comes off as a monster at times, considering she has horns, a tail, fangs, wings, and her food source is men's essence, which leaves normal men DEAD after she drains them. The demons in the forest are guilty too, because yeah they were really nice to Lute once they realized who he was, but apart from him? They (rather brutally) killed at least 2 of the other soldiers that had been on the expedition (and wiped out ALL previous expeditions that had been sent in), AND later in the story they stated outright that they were attempting to cook and then EAT Isis via boiling her.
- Demons meanwhile see humans as monsters based on their actions toward them and each other. It was said that many humans in the past have tried to steal power from demons to control them as well as use against other humans. Lute's father, the previous demon king, had actually killed a tyrannical human 1000 years prior to the story, during that human's attempt at stealing god-like demonic power from the demon's sacred temple. Then, supposedly 50 years before the story, demons were apparently targeted for mass execution by humans (for reasons unknown since the last big clash they had had with humans had apparently been 100 years before the story and thus 50 years prior to the issuing of the Demon Execution Order), so most demons either went into hiding in plain sight, fled, or took to living in isolation from human society in the Demon Woods.
- How is it that if demons are so powerful (which they demonstrate many times throughout the story), they've nearly been wiped out by humans?
- One may think that perhaps they aren't as "extinct" as humanity thought. Plenty of demons encountered in the story had been living away from human civilizations.
- There's also the idea that some demons took to hiding in plain sight among humans (such as Luceria's mother). Or if they have powers like Shamsiel's, they could technically come and go just about anywhere they pleased so long as they were careful.
- The story reveals that his daughter, Princess Luceria is half-human, half-nymph (a type of demon). It goes on to say that thanks to this, Luceria's body has lethal magical properties similar to that of a succubus, so any normal man who gets intimate with her would either lose their mind or die. Lute negates this (after struggling initially), thanks to being half-incubus which is the highest class of demon in their world. However, how then was King Hagel I able to survive being with his 2nd wife who was actually a genuine Nymph? The Prime Minister even stated that no human had ever copulated with a woman and lived to tell about it. It is said that Bobon is a normal human (though his demeanor suggests he might be part-man part-stupid-cow), and he was King Hagel I's firstborn son from his first marriage to a royal family member from the Lingobard kingdom who (as far as we know) was a normal human too. Again, what was it about him (a supposedly normal human) that made him able to survive his relations with a full-blown Nymph for years (and it wasn't a once-in-a-while thing either, in Luceria's route, the King makes comments that suggest Luceria's mother and had sex almost every night even before they were married)?
- Shamsiel makes a few comments that MIGHT hold the answer. At one point she says that she had seen royal families of humans mixing with demons in secret similarly to the King and his 2nd wife. That COULD mean that maybe King Hagel really IS part demon, but it would have been enough generations back to where he has pretty much no demonic traits nor the smell of a part-demon person, yet still has the single characteristic of being able to have relations with a nymph and not die or suffer any negative side effects from it. In essence, this could mean that even Bobon would have some small connection to the demons which in turn allowed him to enter the 2nd temple before Lute and Shamsiel in her route. However, the problem with that is that in Isis' route he had approached the 1st temple with the Guardian Tree but was unable to get it to listen to him, so it raped him to death. The plot thickens...
- The sequel/side story Kyonyuu Fantasy Gaiden may have provided the answer. According to characters in said sequel, none of the royal families of any of the kingdoms within the continent consist of entirely human descent. Which means that King Hagel I likely WAS indeed part-human part-(unknown)demon. This may also partially explain why Bobon might have been able to enter the temple in the demon woods, because HE by extension would be part-demon too (though not as much nor as powerful as Luceria his sister or Lute who is half-incubus). Also, even if that all turned out to be true, there would have to have been humans in each of the families able to survive intimacy with demon races, which isn't lethal in all cases, but with those like Succubi and Nymphs it is.
- It's revealed that Shamsiel had known Lute and his family since before he was born. She even visited his family a few times while he was growing up (until he was 3 years old). Then, years later in Boan, when she first sees Lute she says, "Long time no see. You've gotten big~" and "You're Lute right?" as though she already recognized him. Why then does she still have sex with him (his first time), knowing who he is and that it might kill him (in fact, much of what she says during seems like she IS trying to kill him). They explain in at least Shamsiel's own route that immediately following their first night together, she recognized him from their past meetings, but she didn't tell him out of a desire to let him live his life freely how he wanted... Again though, Why then does she seem to both recognize and yet still seem to try to kill him during that first night they're together in Boan?
- One possibility could be that she had been scouting the town for new targets when she heard rumors that the Prefect had apparently hired a man named Lute to exorcise the demon, which she took as a challenge, so she could have learned his name and some basic facts that way, yet at the same time she wouldn't have fully recognized/realized he was someone from her past until AFTER they finished. (Honestly, she probably figured some of it out when he first grabbed onto her boob that first time, but she was probably too distracted by the sensation to bother thinking about it in the heat of the moment.)
- The Prime Minister is the big bad of the visual novel and anime. Sure he does a lot of evil and despicable things over the course of the story, but what exactly was his goal or reason behind doing all of it? Some of it doesn't add up: He claims to be the one secretly holding all the real power in Edelland, and yet the King is actively trying to enact political reform from a noble-based system to one where knights would be placed in charge of the territories of the kingdom. Was the Prime Minister for or against this? Sure, he hated the Royal Knight's Academy, but he also spoke in support of the new system. But then, he was secretly instructing Bobon into stirring up a rebellion in Boan, and even ordering Whan Crayon into playing the rebels in Inland and the King's forces into fighting each other. It gets even stranger when you realize that IF the rebels had attacked the King's forces, they could have wiped them out and even marched on the capital of the entire Kingdom and likely won. Which likely wouldn't have ended well for the Prime Minister since Gladys, the leader of the Rebels, has had a long-standing feud with him. So why make it so her forces could win? Then, there's Prince Bobon. Anyone who has ever known him for 10 seconds, knows that he's too much of a spoiled idiot to be fit for ruling anything, yet even before the Prime Minister murders the king and puts Bobon on the throne, he was already setting up for Bobon to take the throne, such as having his grades altered in the Royal Knight's Academy, trying to have him stir up revolt in Boan which would have likely led to the neighboring nation of Lingobard invading in support of Bobon, but again. How does that benefit the Prime Minister? Had that revolt happened, it would have actually clashed with Gladys' forces AND an invasion from Lingobard would mean that instead of Bobon inheriting the throne legitimately, it would be more likely that Edelland would be annexed or conquered by Lingobard so then Bobon would have Lingobard's support and connections protecting him. In which case, the Prime Minister would either have been replaced by someone FROM Lingobard, or even if he were left in office, he wouldn't be able to go against Bobon since Lingobard would have immediately suspected him and had him executed for it. In Isis and Shamsiel's route, he also does the strange thing of sending Bobon with instructions on how to navigate the Demon forest and try to steal the power from the temple. Why wouldn't the Prime Minister just take that power himself? Where did he learn all he knew about said forest and demon temple already? What did he think Bobon could possibly do with god-like power that would be of any benefit to him (the Prime Minister)? So again, what exactly WAS the Prime Minister's goal in all of this? (It definitely was NOT to just maintain the status quo.)
- A possible answer is implied in the Harem Route, where the Prime Minister keeps adjusting his plans to fit the current circumstances and expects people to go along for them by playing on their apparent lust for power in exchange for cooperation, even though he later admits some of those plans were ill conceived later, suggesting he's addicted to concocting Evil Plans.
- That does sound like a plausible explanation. In the anime adaptation, the Prime Minister puts on more of a goofy front even speaking differently when talking to the King and agrees with everything he says, at least in front of him, but is all the while plotting even more stealthily behind everyone's backs. The kicker though, is something he says after suggesting Lute be sent to deal with Gladys. After dismissing Isis with orders to pass to Blan Cerfan, he thinks to himself "What a fool he is. Regardless I must force the Royal Knight's Academy to make a grave error before I die." That sort of makes it seem like he IS against the Royal Knight's system, but why exactly isn't explained. It could be that even HE was under orders from someone or something else that was having him conspiring to not maintain the status quo at all, but actually work on the Kingdom's eventual collapse. In which case, that WOULD explain why he was trying to manipulate Gladys' rebels and the King's Forces into fighting. It also explains why he would have sought to have Bobon stirring up trouble in Boan. Had that rebellion actually taken place, the Royal Knight Academy's reputation would have suffered as would the King and the new system reforms he was trying to enact. In the event that Edelland WERE to be conquered or broken apart by civil war, then all its lands and resources would be within someone else's grasp. INCLUDING the demon forest and access to the temple deep within it. Maybe his goal wasn't to secure it for himself, but for someone else. The more I think about it, the more that DOES seem plausible, because then it also explains how he knew so much about the demon forest and the temples, AND maybe his sending Bobon out there could have been a test to see if there really was a way to gain god-like power from it. (Again, maybe not necessarily for himself, but whoever he was under orders from.)