In the field of Clinical Thanatology, we focus on ethical decision-making process in healthcare regarding life and death, which directly affects not only the final destiny of an individual’s body but also that individual’s daily life and life plans. Life and death decision-making involves many factors, such as a person’s own current health condition, the entirety of his/her life, their family members, healthcare providers, and society as a whole. From these points of view, we inquire into what the decision-making process should be, considering the one in the medical treatment, the one in the end of life, and the various values and dignity of an individual’s life.