Ajin: Demi-Human

Ajin is a seinen manga written by Tsunina Miura and drawn by Gamon Sakurai.

Plot
Those who are resistant to death are called "Demi-humans".

That day, Nagai Kei, a High school student, should have died in a traffic accident, but he comes back to life shortly after. In other words, Kei is a demi-human. Since then, Kei's world changes dramatically. Terrified and without knowing what is going on, Kei is saved by his friend, Kai. Together, they flee deep into a deserted mountain. Later, a group of demi-humans who are hostile against humans contact Kai… Who is he fighting against? Who should he side with?