Immortal Hounds(2013)

Shinazu no Ryouken

In another reality, humans never die. If they get sick or injured, they simply "kill" themselves and immediately come back to life. But then a mysterious disease, Ressurrection Deficiency Syndrome, starts spreading through the populace via Vectors. A task force is determined to solve the mystery of RDS but a group of escape artists hamper their efforts.

(Source: Kodansha USA)

Note: Includes 5 extra chapters.