Ajin Part 2: Shoutotsu  

Ajin: Demi-Human Movie 2: Confront, 亜人　第２部「衝突」

Unfortunately, Kei's newfound immortality has not granted him any superhero abilities. Instead, he is viewed as an unusual individual by both society and governments, who see him as a valuable subject to be studied and experimented on in order to further understand and potentially harness the benefits of immortality for humanity. Despite this, Kei must still face the harsh reality of living out his life multiple times, enduring countless deaths for the sake of scientific advancement.