This article analyzes the relationship between subjective well-being (SWB) and participation in neighborhood associations (NHA) in Japan. While the theoretical and empirical literature suggests a strong positive correlation between participation in NHAs and SWB, recent research on Japan could not validate this result. The present study shows how those diverging results can be explained in light of existing theoretical frameworks such as the self-determination theory. Using linear regression models on data from two different studies, we find that participation in NHAs can be positively associated with SWB even in the case of Japan. However, this positive association disappears (1) when the activity is conducted involuntarily and (2) in the case of men when other activities are controlled for. Finally, we find that (3) controlling for subjective loneliness has in some cases detrimental effects on the positive correlation between NHA activities and SWB.