This paper provides a comparative analysis of two communities in Japan based on long-term anthropological fieldwork: one is the community of those with hattatsu shōgai (developmental disorder) and their families and the other is the community of those who have experienced hikikomori and their families. The purpose of this paper is to examine the similarities and differences between the two communities in terms of the ways in which medical diagnoses are understood, identities are formed and certain perspectives on society are shared. By doing so, we attempt to move beyond the clinical sphere to capture the sociocultural significance of "being" an individual with developmental disorder or hikikomori experience.