Ajin is the new Sei no Kakuritsu in my opinion because, the key about these two series is the suspense. Kei reminds me about Shinichi in some ways like :The poor main character who wants a normal life but, BOOM something comes on and change his entire life. Also,while Shinichi has Migi, Kei has his phantom or whatever it is.
"They are not human... right?"
All of a sudden an ordinary high school boy realizes he's not a normal human anymore, he begins to struggle trying to find a safe place in such a cruel world being despised by society.
Is he not a human, or are humans not humane enough?
They have the same "kind" of forced unfair situations that lead the main characters go "wild"
Dark and cruel world. A fight between humans and parasytes/Ajin.
Both anime have a school boy who's pretty much innocent and naive, and finds himself to be the parasyte/ajin.
Lots of action, violence, gore, fight between humanity and ajin/ghouls.
Psychological, questioning morals of what's good and bad/right or wrong, and humanity.
Shinichi has Migi, Kei has IBM ( Invisible Black Matter) who fights and protect them.
Supernatural creatures reside in humans and they possess special ability. Due to that circumstances, the community despise them and hunt for them.
* Both series shows supernatural beings ( Parasytes & Ajins ) being hunted by humans...
* Both shows are dark and dramatic...
* Both MC's ( Shinichi & Kei ) becomes cold hearted killers ( mostly for self defense )
* Both Shinichi & Kei has helpful people around them...
* Both are intense as hell...
* Both has dislikeable antagonists/enemies...that makes you want to punch your monitor
* Both has outstanding BGM 's...(truly perfectly fitting)
A young man discovers an amazing ability. He handles it in his own way. Violence ensues regardless of how well he handles it.
-Are commonly associated with Tokyo Ghoul, but are much better.
-Have a dark theme
-Have a protagnist that is wimpy at first look, but can be serious when needed
-Protagonist is inhuman and hides his abilities
- Similar themes.
- Both reagrding young people coming to terms with a strange power that separates them from normal humans.
- Both are serious, complex, and well-written.
In both there are humans that need to hide because of supernatural stuff. The Ajin need to hide because of their abilities which the government wants to exploit and experiment on. In Kiseijuu the parasites are aliens that want to hide because of their plans and the main character is someone that kept control over his body and is all by himself like the main character in Ajin.
Both are involved/confronted with others of their "race" what want to harm humanity. And they don't want to work together with them. (Which means they need to hide from other humans and from others of their "race".)
Two mutated teenagers. Going through live problems. Both MC's are getting hunted down. Revolve around live issues. Very indulging anime.
If you like Action, Horror, Psychological, Seinen... And of course Fantasy (Kiseijuu is Sci-Fi, while Ajin is Supernatural), you'll enjoy these animes.
There are big changes in high school students' lives, when they realize they aren't ordinary humans anymore. They're trying to live peacefully, while humans are hunting "monsters" (parasytes or demi-humans) and monsters are planing to take governance in their hands. But things aren't going as well as protagonists wanted to...
And both animes have similar atmosphere, so if you liked Kiseijuu: Sei no Kakuritsu, you should watch Ajin.