Zero at the Bone (Manga)

After witnessing a mob hit, surgeon Jack Francisco is put into protective custody to keep him safe until he can testify. A hitman known only as D is blackmailed into killing Jack, but when he tracks him down, his weary conscience won't allow him to murder an innocent man. Finding in each other an unlikely ally, Jack and D are soon on the run from shadowy enemies. Forced to work together to survive, the two men forge a bond that ripens into unexpected passion. Jack sees the wounded soul beneath D's cold, detached exterior, and D finds in Jack the person who can help him reclaim the man he once was. As the day of Jack's testimony approaches, he and D find themselves not only fighting for their lives... but also fighting for their future. A future together.