Before the Second World War, Osaka was called the Manchester of the East, because its industries, such as cotton spinning and metal work, played such an important role in the national economy. Osaka had also been a primary commercial centre of the country since the seventeenth century. It is, therefore, no exaggeration to say that Osaka was the centre of Japanese capitalism, and it was during the Taisho era, 1912–1926, that Osaka was most prosperous. In those days there was unceasing immigration to Osaka, particularly into the urban area, in order to find employment. The migrants came primarily from rural areas, plus an increasing number from Korea. Under such circumstances, acute social problems emerged, in particular slums, unemployment and poverty.During the Taisho period, the Osaka authorities were not unaware of the problem of poverty. First, the local authorities began to recognize the necessity of a municipal social policy and so they reorganized the administration in order to attack poverty. With this reorganization, a new department was formed to deal with all aspects of the social welfare of the inhabitants. Secondly, they actively carried out and published social surveys of urban poverty. From the information thus obtained, a relief system was established, consisting, for example, of social work and public assistance. Thirdly, urban officials accepted the responsibility of coping with urban poverty and actually made efforts to tackle it. They tried to define the meaning of poverty and the attitude of the local authorities towards poverty changed completely from that which had obtained in any previous period. It was in this era that the actual living and working conditions of the urban poor became apparent to the authorities and practical measures were taken to ameliorate poverty. For these reasons, Osaka provides us with an interesting case study.The focus of this article is on the relationship between poverty and family formation in Osaka, including not only the circumstances of the urban poor but also the factors influencing the attitudes of the local authorities, who recognized the importance of the relationship between urban poverty and family formation, and the nature of the relief system they organized. Before going into detail concerning Osaka's poverty problems between 1912 and 1926, however, it is necessary to examine the set of circumstances which, one might argue, were critical in prompting Osaka to launch a social work programme.