The intro is good with some mystery using history biology and religions reference combine with Japanese mythology
For example:
Alister Crowley, The tree of life, 23 element of Sephiroth, evolution, etc
However, nothing is fully explained so you just need to accept that it is because it is. The character just show they knowledge so the audience can feel more and more mystery about the story. It's good that you can enrich your knowledge by reference in this manga as the example I stated above. However, you will never wonder and think more about them.
The character was fine, I guess except the female friend of MC was so annoying. I understand that she love him so she worry about him but the way she act make me just want she die everytime she appear and the MC must be very patient to be with her.
The villian motive is vague.
- In his first flashback in high school, he met inugami while trying to to rape a girl (unidentified at this time). At this scene, it's suppose they were friend lover according to their look and act toward each other.
- Next flashback is the meeting with his daughter whose's mother is the girl she was trying to rape in 1st flashback. It is unknown how she is pregnant with his baby, by the rape incident or later event happened but they are not husband and wife and they attitude is not friendly anymore so there must be some incident between them
- Next flashback show he and his elder sister, it is somehow show that he loved his sister as a man and woman
- It is implicitly state that the girl he was trying to rape was his sister. So he committed incest. His sister rejecting him caused him trauma (or so I think)
- He said that he trying to create a new kind of species with his DNA
So after all of those information, his motive is unclear. At first, I thought that he want to be with his sister again because at that time it look really like Evangelion to me. However when he said his goal and his reason is because
he refuse to grow-up to adult but his sister want to grow-up so he can't achieve his goal at that time. This make me confuse because now his motive contradict with his flashbacks
So I must called this is bad development.
And also, at the end of the series, there isn't any explanation of the origin of 23 and zero. Their origin are mixed with many reference but nothing come clear. Let look at Evangelion, they use same supernatural and confusing stuff but if you can get the hint you have the idea of story and how thing happen but with this manga, you can't
I would give it 7/10 as it is not bad but not very good either however you can still read it volume to volume if you can just ignore the annoying MC's female friend
