Spoiler! :
So, I finished it just now.
First things first - great job. I'm super impressed at what you've done and it was a lot of fun to read.
The thing I enjoyed the most was the characters and interactions between them. You really nailed the character personalities and the dialog is a blast.
Other immediate impressions:
Nooooo! Kureha! You Itsuki! I didn't see this coming and thought you handled this fantastically. Each character's reactions turned out very interesting.
Did Ageha really go kill that one guy in Akiba dressed as Ichigo (Bleach)? I wasn't exactly sure who he was supposed to be because you didn't describe the costume enough, but this was hilarious.
Great job with the action scenes. I often have a hard time following what is going on in fights, but most of the time I could understand what you were getting across with the action flow.
You included some "typical harem moments" but with your own unique twist, which I thought was great. The comedy moments and dialog are good and actually funny.
Now for the negative.
I feel like some of my criticism might come off as a little harsh, so try not to take it the wrong way. Keep in mind that overall I really liked it. None of this is saying you did a bad job or anything, just writing a novel is a ton of work and needs a lot of iteration.
My number 1 complaint, far and above anything else, is the editing.
I really struggled through chapter 1 and 2 until I was able to just turn off my inner editor and read the story without worrying about that stuff. It still kept popping back up throughout the novel and bothering me, though.
There were a lot of instances of incorrect tense usage ("has" instead of "had" was the worst).
While your word choice was pretty good most of the time, sometimes it was very confusing (sorry, no examples off the top of my head).
There is some unnatural dialog in a few places.
The whole thing really needs at least another edit pass, if not more.
Other complaints:
You left me wondering what ARMS stood for for a very long time (like ch 3 or so?). Some lines might have been unintentionally funny. Like in chapter 1, "I hope he doesn't have any ARMS." I don't think you needed to explain the acronym so early, but a short mention of it being cybernetic enhancements would have helped a lot. You wouldn't want to do the explanation in Ageha's thought line, but maybe an earlier line describing Ageha taking advantage of his own ARMS would have been good.
My confusion over ARMS was only surpassed by me wondering what NGC stood for until the epilogue. Going back, it looks like you used the full name in chapter 1, but you didn't use the acronym at the same time! Maybe other people reading it didn't have this problem, but I was pretty confused. A simple "Nikdaou Group of Companies (NGC)" might have solved this issue.
Early on, there is the stuff with the Excell company, but later you started calling it Exceed? Was this just an error or is it 2 separate companies? I was confused.
In a few places, the dialog got confusing. I've noticed a lot of LNs do this and I don't like it in those either. Most of the time I could follow, or count back and see who said what, but sometimes in the 3 person conversations I didn't know who said a line. It also gets confusing when someone says something twice in a row. I only had this problem like 3-4 times, so it wasn't too bad. You don't want to add in too many things to break the dialog, so I understand what you were doing. The back and forth between Kaika and Ageha, for example, is well served without anything extra.
I was pretty confused by the brothers talking about Saionji. Maybe I missed something but didn't think Saya was supposed to be anyone important in the company. Then it turns out she's on the board? This was really confusing for me as I thought she was just some random person that Kaika picked up as her butler.
Saya's art - it looks like you basically copied Tokyo Ghoul's Touka. The hairstyle is so similar that I wouldn't be surprised if you said you traced it. Also, this is my personal preference, but the hair covering one eye thing just looks dumb to me. All that said, I did like her character.
When they're in the museum vent, it wasn't clear why Saya couldn't just crawl a little further along to let Ageha do his thing. This could be easily resolved with a line mentioning that the vent ended here, or something, making it impractical to back out.
I don't know french or fancy dining terms. It would be great to have some notes or something at the end of a chapter so I don't have to go look up what primo and secondo or cucina means. The food terms were also all completely lost on me. This wasn't a big deal, though.
Other random thoughts:
I can't believe you didn't have a picture of naked Kaika barely covered by random things in the scene. You really let your readers down here
You should have a link with all of the illustrations.
On the illustrations, I always like illustrations, and yours weren't bad. I wouldn't say they're great, though. I love the cover.
*Scrolls up* Man this is a lot of feedback. Hope this is what you wanted from my review.
Overall, again, fantastic job. I really enjoyed it and am looking forward to volume 2!
Things I think would be neat to expand upon in the future:
Ageha's grandfather/family
The kids from the flashback in the present day
What made Ageha into a crazy murderer
Fleshing out the setting a more
I think you have a lot of potential with what you've set up here.
First things first - great job. I'm super impressed at what you've done and it was a lot of fun to read.
The thing I enjoyed the most was the characters and interactions between them. You really nailed the character personalities and the dialog is a blast.
Other immediate impressions:
Nooooo! Kureha! You Itsuki! I didn't see this coming and thought you handled this fantastically. Each character's reactions turned out very interesting.
Did Ageha really go kill that one guy in Akiba dressed as Ichigo (Bleach)? I wasn't exactly sure who he was supposed to be because you didn't describe the costume enough, but this was hilarious.
Great job with the action scenes. I often have a hard time following what is going on in fights, but most of the time I could understand what you were getting across with the action flow.
You included some "typical harem moments" but with your own unique twist, which I thought was great. The comedy moments and dialog are good and actually funny.
Now for the negative.
I feel like some of my criticism might come off as a little harsh, so try not to take it the wrong way. Keep in mind that overall I really liked it. None of this is saying you did a bad job or anything, just writing a novel is a ton of work and needs a lot of iteration.
My number 1 complaint, far and above anything else, is the editing.
I really struggled through chapter 1 and 2 until I was able to just turn off my inner editor and read the story without worrying about that stuff. It still kept popping back up throughout the novel and bothering me, though.
There were a lot of instances of incorrect tense usage ("has" instead of "had" was the worst).
While your word choice was pretty good most of the time, sometimes it was very confusing (sorry, no examples off the top of my head).
There is some unnatural dialog in a few places.
The whole thing really needs at least another edit pass, if not more.
Other complaints:
You left me wondering what ARMS stood for for a very long time (like ch 3 or so?). Some lines might have been unintentionally funny. Like in chapter 1, "I hope he doesn't have any ARMS." I don't think you needed to explain the acronym so early, but a short mention of it being cybernetic enhancements would have helped a lot. You wouldn't want to do the explanation in Ageha's thought line, but maybe an earlier line describing Ageha taking advantage of his own ARMS would have been good.
My confusion over ARMS was only surpassed by me wondering what NGC stood for until the epilogue. Going back, it looks like you used the full name in chapter 1, but you didn't use the acronym at the same time! Maybe other people reading it didn't have this problem, but I was pretty confused. A simple "Nikdaou Group of Companies (NGC)" might have solved this issue.
Early on, there is the stuff with the Excell company, but later you started calling it Exceed? Was this just an error or is it 2 separate companies? I was confused.
In a few places, the dialog got confusing. I've noticed a lot of LNs do this and I don't like it in those either. Most of the time I could follow, or count back and see who said what, but sometimes in the 3 person conversations I didn't know who said a line. It also gets confusing when someone says something twice in a row. I only had this problem like 3-4 times, so it wasn't too bad. You don't want to add in too many things to break the dialog, so I understand what you were doing. The back and forth between Kaika and Ageha, for example, is well served without anything extra.
I was pretty confused by the brothers talking about Saionji. Maybe I missed something but didn't think Saya was supposed to be anyone important in the company. Then it turns out she's on the board? This was really confusing for me as I thought she was just some random person that Kaika picked up as her butler.
Saya's art - it looks like you basically copied Tokyo Ghoul's Touka. The hairstyle is so similar that I wouldn't be surprised if you said you traced it. Also, this is my personal preference, but the hair covering one eye thing just looks dumb to me. All that said, I did like her character.
When they're in the museum vent, it wasn't clear why Saya couldn't just crawl a little further along to let Ageha do his thing. This could be easily resolved with a line mentioning that the vent ended here, or something, making it impractical to back out.
I don't know french or fancy dining terms. It would be great to have some notes or something at the end of a chapter so I don't have to go look up what primo and secondo or cucina means. The food terms were also all completely lost on me. This wasn't a big deal, though.
Other random thoughts:
I can't believe you didn't have a picture of naked Kaika barely covered by random things in the scene. You really let your readers down here
You should have a link with all of the illustrations.
On the illustrations, I always like illustrations, and yours weren't bad. I wouldn't say they're great, though. I love the cover.
*Scrolls up* Man this is a lot of feedback. Hope this is what you wanted from my review.
Overall, again, fantastic job. I really enjoyed it and am looking forward to volume 2!
Things I think would be neat to expand upon in the future:
Ageha's grandfather/family
The kids from the flashback in the present day
What made Ageha into a crazy murderer
Fleshing out the setting a more
I think you have a lot of potential with what you've set up here.