This study examined whether perceived partner responsiveness in romantic relationships would moderate the association between communal orientation and subjective well-being. An online survey was conducted among 516 Japanese adults involved in romantic relationships. Participants first completed the Communal Orientation Scale and answered questions about their perceived partner responsiveness. Participants were then asked to recollect their experiences when they provided benefits to their partner in the past month and to indicate their feelings about these experiences. Finally, participants completed scales measuring subjective well-being (Life Satisfaction Scale and the PANAS). The results revealed a positive association between communal orientation and subjective well-being, observed only among those who perceived high partner responsiveness. Contrary to the hypotheses, moderated mediation effects of participants’ felt authenticity and regret in providing benefits to their romantic partner were not found. These results suggest that communal orientation is more likely to be associated with one’s well-being when individuals feel secure about their partner’s responsiveness.