Fuji no Yamai wa Fushi no Yamai. (Pilot)

A catastrophic event has thrust the world into an age where disease begets disease. Ostracized for his unconventional treatment methods, the dark Doctor Ikuru is stricken with an immortalizing disease. On a desperate mission to die, he must save a world desperate to live. Go to the very edge of humanity and back in one man's search for an ending to his suffering, all while saving the world he wishes to leave. Source: MU