Social capital, defined as relations of reciprocal support, is thought to enhance a group's capacity to attain a common good. In Japan, social capital ties permeate much of political society. One would expect that social capital would facilitate parties to arrive at equitable labor policies and reduce overt political conflict in Japan. Has this cooperation occurred, or has labor been coopted? My study addresses this question through the analysis of networks among organizations active in labor-related policy decisions. I focus on Japan with some reference to the United States. The analysis shows that, indeed, networks of social capital weave together government, business, and labor very tightly in Japan (but only labor in the U.S.). The more tightly social capital ties labor to the state, the less it differs from the state's preferred policy. Intense differences of material interests, though, as indicated by the case of a health care policy decision, weaken this integrative capacity of social capital. The Labor Ministry tries to use social capital to build consensus between labor and business, but diverging interests erode such consensus. These findings indicate that dense networks of social capital, while facilitating consensus, do not erase opposed material interests.