Deathless Bride

Gene is an immortal man. Because his body regenerates infinitely even when cut to pieces, he has been imprisoned in a laboratory and has had his body sliced open almost every day. Having lost his memory, the only person he can trust is a mysterious girl who visits him every day. However, one day, a conversation with the girl triggers the return of his memories... A dark fantasy of immortal love.

(Source: Natalie, translated)