This article demonstrates how debate about technologically manipulated death is elaborated in radically different forms in the scientifically sophisticated spaces of Japan and North America. Using recent historical materials and contemporary medical, philosophical, and media publications, I argue that the institutionalization and legitimization of "brain death" as the end of life in North America have been justified by a dominant discourse in which it is asserted that if certain measurable criteria are fulfilled, an individual can be declared scientifically dead. In Japan, by contrast, death is interpreted primarily as a social and not an individual event, and efforts to scientifically define the end of life as a measurable point in time are rejected outright by the majority, including many clinicians. The margins between nature and culture are debated in both cultural spaces, but assigned different moral status in the respective dominant discourse.