This is such an amazing concept! I don't have time right now, but I will read to rest! Gosh, sorry for the short review. Hopefully I'll leave longer ones when I finish other chapters. In any case, you've got a good thing going so far. It looks like it'll be something of a reverse-harem (?) with Mayu; can't wait to see how she interacts with these five demon boys. And Mother Matilde is definitely a character. I'd love to learn more about her, too!

"Mayu mumbled hoarsely before fleeing the room, the push still gripped in her fingers."

Did you mean 'plush' instead of 'push'?

"It's you're fault she's dead!"

Ah. That again. "your" instead of "you're".

Kaito rolled over across the room? Www I started to imagine it and found it funny.

This chapter revealed Yuuma's flashback with his sister, Flower. Honestly, I thought it would be Mizki haha. The chapter has shown Mayu with emotions too! It was clearly written but there were still hints of her being a standstill robot.

I read this chapter twice to understand it. Also, I find myself puzzled over the time the story was set. Was it the first fall? Or somewhat another?

More backstory on how everything happened, please. It might confuse others; but for the other criterion, which is the flow of the story, grammar, etc etc, it is good but there are error in some.
Like what I said before, don't think too much about this! Hope you have a nice day.

Oooh. I'm quiet getting into it. When Kaito thought to how Len managed to bypass Mother Matilde, or Meiko, with his weapon, it just made me wonder. Did Meiko have the demons on her palm too? She's really mysterious and I can't wait to see her again in the story.

I saw a typo in this story. "Mikup" instead of "Mikuo".
Some grammar errors.

"Did that brat do this to you?"

Instead of 'this', use 'that'. The arm of Mayu was not being held anymore, right?

Nah. There are no other errors on this one except from those above. Gladly, I would like to say that your story really has a potential! It's kinda a bit like the otome game, Amnesia, to which the MC is emotionless. Though on this one, Mayu goes through an impressive character development along with the others. And also if it could be possible, do add more descriptions of her surroundings. It seems bland. The conflicts are really short too. There are main points and the story is kinda drifting away from the main plot. Mayu does have to know more about the demons, but you should focus more on the plot and have to answer some questions that are getting into someone's mind.

Eep. Don't mind me. Write anything that you want. It is up to you if you'll listen to me anyway. Hoho. I'm just a reader; after all, you can't please everyone right? Do update if you can! Take your time and keep up the good work !

I JUST CAN'T- HAHAHAHA

It really did gave a gag out there! Though it was broken upon the outrage of Mikuo.
Ah also, please do add a bit of emotion on Mayu. She's an artifical angel, or something like that, but she's still an angel right? So she has to remember stuff taught to her or some emotions that could suddenly erupt out from her which can be really surprising. Emotionless as she is, another reader may find her boring or bland. She's really robotic, to be honest. I can predict her actions, too.

Anyways aside from those stuff like those, it is still amusing! Character personalities that you have made are still intact, and flow of story is still good! Keep up the good work!

I always (well.. Since the previous chapter...) refer Mikuo's personality with the song, Tokyo Teddy Bear, but it was broken ww
I kinda forgot that he's manipulative, so I just kinda liked his character with being gloomy and overattached to the teddy bear.

Ah. I kinda saw some spelling error? It was 'singeing'. I know it might be a bit too much of me for being demanding, but I was just pointing it out. It's singing, supposedly, but don't get too worked out about it! Sometimes writers do get confuse with some words (whose, who's; its, it's, their, there, they're; etc) and some spelling, but the plot still flows smoothly so no worries.

Please don't overthink about this! I would also like to say that please write no matter what! I am also looking forward to Mayu turning into a yandere. Hoho. Oh btw, you should a bit kinda explain about more about what the Princes are after, aside from the political power. The 'breaking' of Mayu that they always talk about is a bit confusing.

Slowly and slowly, more characters are being introduced! I'd like to think Gumi is a girl though ww

It's a mansion/manor/whatever right? If I could suggest, I would like more description of Hell outside? It would at least let her realize what has she gotten into, making more emotions to fill her as time passes during her stay in there.
There should be other kinds of demons too, like succubus or incubus, dybbuk, poltergeists, some sort of spectre, etc etc.

It is up to you though! They were just suggestions, after all you're the author!

Ah. Kaito freaks me out. He seems... Creepy, but a bit better than the sort of chill Len gives me. /shivers

LenLen is really like a demon. Now I'm starting to search for a prince of hell that is almost close to his name or likely affiliated with his personality! Www

The coldness of Mayu is really depicted well! She's a bit robot-like, which I think you purposedly did? I am also starting to see character developments to her, especially after the part when the gag was taken off her. Her curiosity finally gave in!

Hi hi! It has been a long time since I read some Mayu fanfics and now another story of yours piqued my interest!

I really like your writing style, especially with descriptions and the transitions of events. They all connect to each other (even if it was just in Mayu's PoV), making the story to flow smoothly which allows the reader to understand it clearly.

'Two Nephilim women, who's clothes indicated they were maids...'

I think you got confused with "whose" and "who's" at that part. Just reminding you on that!

Anyways, I'm also really looking forward to "I'm your Devil!". I haven't looked up on it for a long time, and with you A/N, I just suddenly remembered with my obsession about the Mayu/Yuuma pairing www

Well, I hasn't been here in a while.
Love what you've done with this.
Just the little argument there, ah, perfect.
Also, I've forgotten, aren't there meant to be five demons or something and I'm pretty sure we've only met four, I could be wrong but I'm just not sure...

And so now she has more people chasing after her! Let the challenge begin huh?

This is really good. I really like Mayu, and I'm so glad I found a good story of her.

I particularly enjoyed the interaction between Mayu and Mikuo, although it makes me think that this is obviously going to be MayuXMikuo and that the rest of the relationships aren't even worth a look at. Despite how they all appear to at least slowly be falling for her.

I think that maybe going with the whole song in Japanese wasn't the best idea? I know that it's a vocaloid song and that they're singing in japanese and all that, but its still really dull and makes me want to just skip through it because I don't understand any of it. Sorry but that's the truth. Maybe if you know of the english lyrics use those instead with Japanese interspersed through it? But that might be against the rules grrr... Songs and song lyrics get complicated on this site!

I enjoyed the humor on this chapter, it was done well and even made me chuckle a few times hehe. I think you do a good job of capturing mystery, I can't help but want to read more just to find out the secrets of these demon princes and Gumi!

I'm particularly curious about the head angel that's so sneaky. She doesn't seem to have purely innocent angelic intentions at heart...

Another good chapter. Please continue and update when you are ready!

Miku is a toy bear. A toy bear. Love it.

Uwah! I can't believe I didn't see your update! OTL
Anyway, Kaito's character... He seems really mean!
On the other hand, Len, although mean, seems more interesting of the two.
Eheh, maybe it's because of his book collection? Aha, who knows.
Mayu seems intriguing so far! I can't wait to see her character development.

By the way, I'd like to mention something about this sentence:
"It wasn't long before everything went black and she felt her body crumple beneath her."
I suggest you put a comma between "black" and "and"! It's a conjunction, and I think you just missed that when you were writing as there are other conjunctions in this story.

Other than that, keep up the great work! I can't wait for the next chapter!
- Reign

Oh, wow! After reading the summary, I was suddenly interested in this story! I like all the details you put in the story, and I couldn't find a grammar error anywhere! Please keep up the good work!