This article aims to derive a hypothesis about the experiences of community-dwelling older adults who are engaged in their community, focusing on the concept of well-being. This article centers on the idea of well-being to reveal the possibility that community-dwelling older adults may be able to live richer lives through community involvement; instead, they are used as“ community human resources” in this“ life of 100 years.” To reach the goal, three aspects of well-being̶hedonic, eudaimonic, and social well-being̶were examined to consider the diverse experiences of older adults, analyzed through a literature review. This study found no fixed definitions of the aspects described above. However, since they are related to each other, when measuring the well-being of older adults engaged in community involvement, it is assumed that there are not only specific emotions (e.g., aspects of eudaimonic well-being) but also various ways of feeling (e.g., aspects of eudaimonic and social well-being or eudaimonic and hedonic well-being). In the future, it will be necessary to investigate the relationship with the concept of ikigai in Japan.